Dissertations / Theses on the topic 'Copper castings'

Alloys with good toughness and elevated temperature properties like A201 are expensive and can be more difficult to process. This results in the use of heavier but less expensive alternatives in many applications where toughness is of concern, such as steels. Common alloys such as A356 and E357 are relatively cheap and easy to work with. However, these alloys have considerably lower toughness than premium alloys. This research aims to investigate surface modification treatments that could yield better toughness at a low cost in a common aluminum alloy. The process must show significant improvement in said properties, be cost effective, and easily adaptable in a common foundry. Diffusion of coating material into the substrate was investigated with a variety of coating metals. The diffusion process was facilitated in the solutionizing step for the given substrate aluminum in order to strengthen the sub-surface region of the parts. This research aims to provide a platform for further research into the practical effects of the coating and tempering on impact and toughness properties. These samples were characterized by optical and scanning electron microscopy, EDS, impact testing, and tensile testing.

As curvas limite de conformação (CLC) são utilizadas há mais de 50 anos. Propostas inicialmente para o desenvolvimento de produtos provenientes da indústria automobilista em função das necessidades apresentadas pela área, são atualmente aplicadas de maneira geral para a indústria da estampagem na produção de inúmeros tipos de peças, oferecendo previsões de possíveis falhas e/ou defeitos durante as etapas do processo de estampagem. As CLC´s permitem prever o afinamento excessivo, enrugamento, estiramento e é claro, a fratura da peça. As diferenças metalúrgicas existentes entre os dois processos iniciais - fundição contínua (F.C.) e fundição semicontínua (F.S.C.) - resultam em diferenças nas propriedades finais obtidas para uma mesma rota de laminação a frio e recozimentos intermediários do material especificado. Desta forma, torna-se indispensável um estudo sobre a influência dos processos de fabricação iniciais F.C. e F.S.C. com relação à estampabilidade da liga, sendo esta avaliação efetuada através das CLC´s obtidas por ensaios de tração uniaxiais, propostos pelo IRSID (\"Institut de Recherches de La Sidérurgie\"), (lado esquerdo da curva ?2 < 0) e ensaio Erichsen (lado direito da curva ?2 > 0) e do ensaio de Nakazima reduzido em 60%, ou seja, todo o ferramental e os corpos de prova utilizados nos ensaios foram reduzidos em 60% das dimensões mencionadas pela norma ISSO 12004-2. A diferença microestrutural apresentada entre as etapas de fabricação dos dois processos avaliada através de ensaios de determinação do tamanho de grão, limites de resistência à tração, escoamento (0,2%), alongamento (em 50,80 mm), coeficientes de encruamento n, resistência K, ensaios de \"orelha\", levantamento da CLC0, Erichsen e textura, auxiliaram nas conclusões finais do levantamento das CLC´s para os dois processos do material acabado e metodologias. O processo de fundição semicontínua nas condições processadas apresentou melhores combinações entre as propriedades, exceto na formação de \"orelha\" apresentada na etapa intermediaria de processamento do material. Principalmente o parâmetro CLC0 no plano da chapa, resultou em uma deformação ?1 19% (?2 = 0), superior à apresentada pelo processo F.C., deformação muito importante para a fabricação de peças estampadas. Evidenciou-se também uma diferença de aproximadamente 37% entre as metodologias IRSID x Nakazima reduzido na obtenção da deformação plana para o processo F.C. e 31% para o processo de F.S.C.. Nas condições de deformação; estiramento biaxial, tração uniaxial e embutimento profundo, a chapa produzida pelo processo de fundição contínua apresenta melhor desempenho.<br>Forming limits curves (FLC) are used for more than 50 years. Initially proposed for the development of products from the automobile industry in terms of the needs of the area. It is currently being applied in general to the metal forming industry in the production of numerous types of parts, providing predictions of possible faults and / or defects during the stages of the stamping process. The FLC\'s can predict excessive thinning, wrinkling, stretching and of course, the fracture of the part. The existing metallurgical differences between the two initial processes - continuous casting (C.C.) and semi-continuous casting (S.C.C.) - result in differences in the final properties obtained for the same route of cold rolling and intermediate annealing of the specified material. Thus, it is essential to study the influence of the initial manufacturing processes CC and SCC with respect to the formability of the sheets. This investigation is based on the, assessment of the FLC\'s obtained by uniaxial tensile tests proposed by IRSID (\"Institut de Recherches de Sidérurgie\"), (?2 < 0, left side of the curve) and Erichsen test (right side of curve. ?2> 0) and the Nakazima test reduced by 60%. The difference between the sheets obtained in both processing routes was evaluated by the following parameters: grain size, tensile strength limits, yield strength (0.2%), elongation (at 50.80 mm), strain hardening coefficient n, resistance K, \"earing\" test, lifting of the CLC0, Erichsen test and texture where discussed in view of the obtained FLC\'s for both the two processes of the finished material. The semi-continuous casting process in processed conditions showed better combinations of properties except the formation of \"earing\" presented at the intermediate stage of processing of the material. Particularly the evaluation of the FLC0 parameter resulted in a strain in the plate plane ?1 19% (?2 = 0) superior to the sheet obtained by the continuous casting process. A difference of approximately 37% between the IRSID x Nakazima methodologies was also reduced in obtaining the flat deformation for the F.C. process and 31% for the F.S.C. process. However, for other deformation paths; biaxial stretching, uniaxial traction and deep drawing of the results for the continuous casting sheet were superior.

In a high competitive market, the development of new alloys, new applications, price pressure and increases in product forces quality wire manufacturers to ask for increased mechanical characteristics without losing conductivity. As a particular example, development of new copper alloys such as CuZr, CuSn, CuMg and CuAg have been developed for automotive cables. Continuous extrusion is currently the most prevalent manufacturing technology in terms of chemical composition, mechanical properties and electrical properties, resulting in the production of high quality rods. However, continuous casting has good potential to also be adapted to the mass production of various copper alloy wires. Comparison of the continuous casting process to other thermal methods such as continuous extrusion highlighted that, in general, the mechanical properties of continuous cast materials are lower than that of material from thermomechanical methods. However, continuously cast alloys rods are cheap to produce and simple to manufacture. So, the key aims of this research were (a) to increase the understanding of the solidification behaviour of some industrially important continuously cast non-ferrous alloys, (b) to define an increased range of alloys and downstream processing techniques which could be performed using continuous casting technology, (c) to determine improved continuous casting process validation capabilities and (d) to define new capabilities in terms of casting equipment. The majority of this PhD thesis was focused on improving the current continuous casting technologies and development of casting capability of a range of copper and non-copper alloys. The analysis in this PhD thesis illustrated that the metallurgical and mechanical properties of components mainly produced by continuous casting are acceptable, and that this method could be a replacement production method for materials such as lead alloys and various copper alloy rod, e.g. CuMg and CuAg. However, in the case of Deoxidized High Phosphorus (DHP) copper tubes, the performance of the as-cast material was significantly lower than that of from extrusion or planetary rolling process. This PhD thesis also makes comment on the parameters controlling the solidification process in order to improve the quality of as cast alloys rods/tubes. Using specific casting parameters, a significant difference based on tensile strength and elongation percentage has been illustrated, and it was found that these parameters could improve the mechanical properties of continuously cast copper rods and tubes. This significant difference is as a result only of the change in casting parameters, with no difference in the chemical composition of the material, or the general method of production. These parameters were (1) water flow rate, (2) casting speed, (3) pull distance, (4) melt temperature, (5) cleanout cycle, (6) continuous casting direction and (7) super-cooler size. The new knowledge created and understanding gained during the course of this research improved the company’s capability in the marketplace, enabling it to supply equipment with improved competitive capabilities and the potential to enter new markets, leading to sales growth in existing sectors and significant longer-term growth into new technically challenging application areas.

<p>Aluminum alloys are widely used in many manufacturing areas due to good castability, lightness and mechanical properties. The purpose of this research is to investigate copper’s influence on an Al-Si-Mg alloy (A356). Copper in the range of 0.6 – 1.6 wt. % has been used in an A356 aluminum based alloy. In this work a simulation of three different casting processes, sand-, die- and high pressure die-casting has been employed with the help of gradient solidification equipment. The microstructure of the samples has been studied by optical and scanning electron microscopy. Materials in both as-cast and heat treated states have been investigated through tensile test bars  to get the mechanical properties of the different conditions.</p><p> </p><p>Questions that have been subjected to answer are what influence does copper have on the plastic deformation and on fracture behavior and whether there is a relationship between the content of copper and increased porosity or not; and in that case explore this relationship  between the amount of copper and the mechanical behaviour.</p><p> </p><p>It has been analyzed that a peak of mechanical properties is obtained with a content about 1.6 wt. % copper. The increment of copper seems to have a remarkable impact on the mechanical properties and especially after the aging process showing a large raise on the ultimate tensile strength and yield strength.</p><p>Relationship between the copper content and increased porosity could not be found.</p>

The main purpose of the thesis work is based on achieving same mechanical properties on the three different sized bearing housings. The key mechanical property that had to be focused on was the hardness of the parts. In order to achieve this goal, chemical compositions of the parts have studied. However there were some limitations on the composition variants. Allowed variables of the compositions are silicon, nickel and copper. Due to necessity another element, Molybdenum (Mo), was also introduced. After many simulations three different compositions are proposed. Then the feasibility of results of casting simulation software investigated. And finally an optimization guideline has proposed. Chemical composition researches have carried on casting simulation software, which is called Magma5. Following the completion of the simulations phase, proposed compositions trial casted at the company. Subsequent to trial castings cast parts had tested for their hardness values. In order to bring the thesis to completion simulation outputs and trial test results had compared. With the help of a casting simulation software composition optimisation of different sized parts could be easily optimised in order to achieve same results. Many simulations are executed with different composition for the silicon, nickel, copper and molybdenum variants. It was seen that Mo additions significantly increase the mechanical properties of the parts. Nickel and copperacts similarly on the hardness values, however nickel addition reduce undercooling tendency at a greater rate. Good inoculation is vital for the parts with thin sections. Decent inoculation helps to improve the microstructure and helps to get closer results tothe simulated values. However software represents key information aboutundercooled zones on the part. Software ensures 95% to 97% correct values on hardness results.

Although the demand for A319 alloy has increased in recent years, thermal fatigue resistance of the alloy is still one of the most important challenges in engine applications, especially in the newer generation of engines in which cylinder spacing has been reduced. According to the previous studies there are several parameters that improve thermal fatigue resistance such as: low SDAS, fine grain size, low porosity level, and low intermetallic content. Cooling rate has a direct effect on the shape, size, and distribution of the microstructural phases, as well as on the scale of the dendrites, and pore size. High cooling rates can improve thermal fatigue resistance, as a result of fine microstructure and small pore size. On the other hand, thin sections of a mold may not properly fill and “Cold Shuts” may result, if high cooling rates are applied. One approach to balance these phenomena is to use a water-cooled chill where water cooling is activated part way through the casting sequence. This type of chill causes a lower cooling rate initially, when the filling procedure is occurring, and after filling, the cooling rate increases to reduce the microstructure size. The results show that this method has the potential to both avoid cold shuts and miss-runs and improve the cast microstructure farther into castings remote from the chill. A mathematical model has been developed in “ANSYS CFX 12.0” to evaluate the effectiveness of this concept quantitatively. The model simulates the behavior of the Casting/chill interface and also predicts the cooling rates resulting from different casting conditions when using solid chill and water-cooled chill.

Orientador: Eugênio José Zoqui<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica<br>Made available in DSpace on 2018-08-16T15:58:35Z (GMT). No. of bitstreams: 1 Proni_CeciliaTerezaWeishaupt_M.pdf: 17001263 bytes, checksum: 25c148a2e84c82f917de77b96b714fb6 (MD5) Previous issue date: 2010<br>Resumo: A tixoconformação é uma técnica de processamento de materiais no estado semi-sólido que permite a produção de peças com geometrias near net shape com melhores propriedades mecânicas e com razoável redução no custo final de produção, se comparados aos métodos de fundição e conformação plástica tradicionais. Dentro das várias possibilidades de materiais passíveis de trabalho por esta via, as ligas de alumínio são as mais utilizadas, servindo a diversos segmentos industriais. Contudo, o fornecimento de matéria prima próprias ao tixo-processamento está restrito a alguns produtores, justificando a necessidade de aprofundamento e ampliação de conhecimento com respeito às ligas já produzidas por fundição convencional. Este trabalho apresenta um exame da viabilidade de tixoconformação de duas ligas comerciais: AA 2011 e AA 2014. Esta avaliação foi executada em três etapas distintas: 1) análise dos seus constituintes, das temperaturas de fusão e de solidificação, dos microprecipitados existentes e dos tipos de porosidade; 2) reaquecimento de amostras para observar a resposta à globularização em duas temperaturas distintas (duas frações sólidas) e em quatro tempos de espera diferentes, com a posterior análise quantitativa por meio da metalografia; 3) ensaios de viscosidade nas mesmas condições, com posterior análise microestrutural via MEV e EDS das amostras que apresentaram valores de viscosidade muito altos. Os resultados destas avaliações mostraram que estas duas ligas são tixoconformáveis até a temperatura de 610°C, pois apresentaram valores de viscosidade abaixo de 1x106 Pa.s e tensão máxima abaixo de conformação de 1,0 MPa, conforme escolhas adequadas entre tempos de espera e taxa de aquecimento. Porém, também foi constatada a formação de alumina nos poros de algumas amostras após o reaquecimento necessário à tixoconformação, fornecendo um valor mais alto de viscosidade para estas amostras, se em comparação aos valores encontrados em outros ensaios com pouca ou nenhuma formação de alumina. A eliminação de porosidade na matéria prima com a conseqüente minimização do surgimento de alumina viabilizará a tixoconformação de ambas as ligas<br>Abstract: Thixoforming is a technique for processing materials in the semi-solid state which allows the production of parts near-net-shape geometries, with better mechanical properties and reasonable reduction in the final production cost, compared to traditional casting and plastic forming. Among the various possibilities of materials that can work in this way, aluminium alloys are the most used. However, the world provision of raw material for thixoforming is restricted to few producers, justifying the need for deepening and widening of knowledge with respect to alloys already produced by the conventional casting industries. This dissertation presents an examination of the feasibility of thixoforming of two commercial alloys: AA 2011 and AA 2014. This evaluation was performed in three steps: 1) analysis of their constituents, analysis of melting and solidification temperatures, analysis of the existing micro precipitates and quantity and types of porosity, 2) reheating samples to observe the globularization response to two different temperatures (two solid fractions) and four holding times, with the subsequent quantitative analysis by metallography, 3) tests of the viscosity under the same conditions, with subsequent microstructural analysis by SEM and EDS of the samples that showed very high viscosity values. The results of these evaluations showed that these two alloys are thixoformable up to temperatures of 610°C, since their viscosity values were achieved below than 106 Pa.s, and consequently maximum conformation stress of 1.0 MPa, as appropriate choices between waiting times and heating rate were achieved. However, the formation of alumina in the pores of some samples after the necessary reheating to previous to thixoforming, provide a higher value of viscosity, when compared to values found in other trials with little or no alumina. The elimination of porosity in the raw material, with the consequent minimizing the appearance of alumina will make possible the thixoforming of both alloys<br>Mestrado<br>Materiais e Processos de Fabricação<br>Mestre em Engenharia Mecânica

Organic solar cells (OSC) are interesting as low cost alternative to conventional solar cells. Unsubstituted Metal-phthalocyanines (Pc) are excellent electron donating molecules for heterojunction OSC. Usually organic solar cells with Pcs are produced by vapor deposition, although solution based deposition (like spin casting) is cheaper and offers more possibilities to control the structure of the film. With solution based deposition several parameters (like temperature, solvent and etc.) affect the self-organized structure formation via nucleation and growth. The reason why vapor deposition is typically used is the poor solubility of the metal-phthalocyanines in most common solvents. Furthermore the process of nucleation and growth of Pc aggregates from solution is not well understood. For preparation of Pc films from solution, it is necessary to find the appropriate solvents, assess the solution deposition techniques, such as dip coating, and spin casting. It is necessary to understand the nucleation and growth process for aggregation/precipitation and to use this knowledge to produce nanostructures appropriate for OSC. This is important because the nanostructure of the films determines their performance. In this thesis, optical absorption and the stability of 8 different unsubstituted metal Pc’s were studied quantitatively in 28 different solvents. Among the several solution based deposited thin films produced based on this study, copper phthalocyanine (CuPc) dissolved in trifluoroacetic acid (TFA) is chosen as a model system for an in-depth study. CuPc has sufficient solubility and stability in TFA and upon solution processing forms appropriate structures for OSCs. CuPc molecules aggregate into layers of nanoribbons with a thickness of ~ 1 nm and an adjustable width and length. The morphology and the number of deposited layers in the thin films are controlled by different parameters, like temperature and solution concentration. Material properties of CuPc deposited from TFA are studied in detail via x-ray diffraction, UV-Vis and FT-IR spectroscopy. Atomic force microscopy was used to study the morphology of the dried film. The mechanism of the formation of CuPc nanoribbons from spin casted CuPc/TFA solution in ambient temperature is investigated and explained. The parameters (e.g. solution concentration profile) governing nucleation and growth are calculated based on the spin casting theory of a binary mixture of a nonvolatile solute and evaporative solvent. Based on this and intermolecular interactions between CuPc and substrate a nucleation and growth model is developed explaining the aggregation of CuPc in a supersaturated TFA solution. Finally, a solution processed thin film of CuPc is applied as a donor layer in a functioning bilayer heterojunction OSC and the influence of the structure on OSC performance is studied.<br>In den vergangenen Jahren wurden kosteneffiziente nasschemische Beschichtungsverfahren für die Herstellung organischer Dünnfilme für verschiedene opto-elektronische Anwendungen entdeckt und weiterentwickelt. Unter anderem wurden Phthalocyanin-Moleküle in photoaktiven Schichten für die Herstellung von Solarzellen intensiv erforscht. Aufgrund der kleinen bzw. unbekannten Löslichkeit wurden Phthalocyanin-Schichten durch Aufdampfverfahren im Vakuum hergestellt. Des Weiteren wurde die Löslichkeit durch chemische Synthese erhöht, was aber die Eigenschaften von Pc beeinträchtigte. In dieser Arbeit wurde die Löslichkeit, optische Absorption und Stabilität von 8 verschiedenen unsubstituierten Metall-Phthalocyaninen in 28 verschiedenen Lösungsmitteln quantitativ gemessen. Wegen ausreichender Löslichkeit, Stabilität und Anwendbarkeit in organischen Solarzellen wurde Kupferphthalocyanin (CuPc) in Trifluoressigsäure (TFA) für weitere Untersuchungen ausgewählt. Durch die Rotationsbeschichtung von CuPc aus TFA Lösung wurde ein dünner Film aus der verdampfenden Lösung auf dem Substrat platziert. Nach dem Verdampfen des Lösungsmittels, die Nanobändern aus CuPc bedecken das Substrat. Die Nanobänder haben eine Dicke von etwa ~ 1 nm (typische Dimension eines CuPc-Molekül) und variierender Breite und Länge, je nach Menge des Materials. Solche Nanobändern können durch Rotationsbeschichtung oder auch durch andere Nassbeschichtungsverfahren, wie Tauchbeschichtung, erzeugt werden. Ähnliche Fibrillen-Strukturen entstehen durch Nassbeschichtung von anderen Metall-Phthalocyaninen, wie Eisen- und Magnesium-Phthalocyanin, aus TFA-Lösung sowie auf anderen Substraten, wie Glas oder Indium Zinnoxid. Materialeigenschaften von aufgebrachten CuPc aus TFA Lösung und CuPc in der Lösung wurden ausführlich mit Röntgenbeugung, Spektroskopie- und Mikroskopie Methoden untersucht. Es wird gezeigt, dass die Nanobänder nicht in der Lösung, sondern durch Verdampfen des Lösungsmittels und der Übersättigung der Lösung entstehen. Die Rasterkraftmikroskopie wurde dazu verwendet, um die Morphologie des getrockneten Films bei unterschiedlicher Konzentration zu studieren. Der Mechanismus der Entstehung der Nanobändern wurde im Detail studiert. Gemäß der Keimbildung und Wachstumstheorie wurde die Entstehung der CuPc Nanobänder aus einer übersättigt Lösung diskutiert. Die Form der Nanobändern wurde unter Berücksichtigung der Wechselwirkung zwischen den Molekülen und dem Substrat diskutiert. Die nassverarbeitete CuPc-Dünnschicht wurde als Donorschicht in organischen Doppelschicht Solarzellen mit C60-Molekül, als Akzeptor eingesetzt. Die Effizienz der Energieumwandlung einer solchen Zelle wurde entsprechend den Schichtdicken der CuPc Schicht untersucht.

Ces travaux de recherche portent sur l’étude de l’injection du cuivre. Dans une optique d’amélioration des propriétés du cuivre injecté sous pression, deux grands thèmes de réflexion ont été abordés. La première voie de réflexion porte sur l’influence des paramètres de fusion et d’éléments d’alliages ajoutés en faible quantité sur les caractéristiques des démonstrateurs technologiques produits. La seconde partie discute de l’influence du procédé de fonderie en lui-même, notamment au travers de l’étude de deux paramètres : l’influence du régime d’écoulement du métal en fusion dans l’empreinte, et l’influence de l’emprisonnement de l’air sur les propriétés des pièces injectées<br>This research focuses on the study of high pressure die casting (HPDC) of copper. In order to improve the properties of die-cast copper, two main issues were investigated. In the first part, attention is paid to the influence of melting parameters and of addition of alloying elements in small amounts on the characteristics of the specimen produced. The second part discusses the influence of the foundry process itself on properties of die cast part, in particular by studying two parameters : the metal flow type during cavity filling, and the air entrapment

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05. 16. 04 – Ливарне виробництво. - Фізико-технологічний інститут металів та сплавів НАН України, Київ, 2003. Дисертація присвячена розробці параметрів плавки та обробки розплаву вторинної міді з метою отримання методом безперервного литва заготовок з електропровідністю 55 Сименсів та вище. Досліджено вплив вмісту кисню на властивості вторинної міді, що дозволило визначити залежності електропровідності, межі міцності та відносного подовження при вмісту кисню 0,01 – 0,2 %. Визначено збільшення вмісту кисню на різних етапах плавки металу в індукційній печі під час плавки та обробки розплаву вторинної міді. В дисертації запропоновано технологію отримання кабельно – провідникової продукції з вторинної міді за допомогою горизонтального безперервного лиття, що містить чотири етапи: 1. Плавка вторинної міді з відкритим дзеркалом металу (з вмістом кисню 0,15 - 0,2 %). Це дозволяє рафінувати метал від домішок та знижувати рівноважний вміст водню до меж, що не приводять до з’явлення пор. 2. Наведення флюсу: сода, бура, кварцовий пісок (1:4,5:4,5) для припинення окислення міді, вміст кисню при цьому знижується до 0,05 %. 3. Обробка розплаву міді аргоном та розкислення лігатурою “літій - кальцій” (по 50 % кожного), що дає змогу отримати виливки з міді, щільність яких 8940 кг/м3, та електропровідність більш, ніж 58 Сименсів. Витрати аргону 0,7 - 0,8 м3/т розплаву. 4. Горизонтальне безперервне литво з такими параметрами: - швидкість лиття – 0,48 м/хв; - крок витягування – 40 мм; - тривалість витягування кожного кроку – 4 – 6 с; - тривалість паузи – 5 - 6 с. В результаті розробки нової технології скасовано ряд операцій існуючої технології, що зв’язані з литтям вайербарсів, їх фрезеруванням, прокаткою, термообробкою, тощо. Основні результати роботи знайшли промислове впровадження у плавці та обробці вторинної міді.<br>Thesis for submitting a Technical science candidate degree on specialty 05. 16. 04 – Foundry production.- Physico-technological Institute of Metals and Alloys of NAS of Ukraine, Kiyv, 2003. This thesis describes the development of melting and treatment for the smelt of secondary copper for the manufacturing bars with 55 Siemens conductance and more using the horizontal continuous casting. The thesis proposes a new technology for the production of a cable-conductor product from secondary copper based on horizontal continuous casting that consists of 4 stages namely: - melting secondary copper with an exposed mirror of metal (copper includes less than 0,15% of oxygen); - flux melting metal (flux consists of: soda, quarts sand, borax (1:4,5:4,5)), the results of copper includes less than 0,05% of oxygen; - the treatment of molten copper by argon and then deoxidizing by an alloy of “lithium-calcium” composition (50% per lach), the results of copper have density of 8940 kg/m3, 58 Siemens electroconductivity (then flow raze of argon then being 0,8 m3/t copper); - horizontal continuous casting with the following parameters: - velocity of casting – 0,48 m/min; - space for drawing – 40 mm; - time for drawing – 4 – 6 s; - time for pause – 5 - 6 s; - the angle of mould inclination to horizon – 15 O. The horizontal continuous casting has been shown to offer many advantages over wirebarce casting. The basic results of the work have found industrial implementation into the melting and treatment of secondary copper.

Die Anforderungen, in vielen Bereichen des Maschinen- und Anlagenbaus immer mehr Leichtbaumaßnahmen zu realisieren, steigen ständig weiter an. Die Umsetzung von Leichtbaukonzepten wird durch den Einsatz neu entwickelter Werkstoffe und Werkstoffsubstitution realisiert. Es steht fest, dass die herkömmlichen Technologien eine weitere Steigerung der Leichtbaupotentiale nicht mehr gewährleisten können. In der vorliegenden Arbeit wurden neue innovative Fertigungstechnologien zur Herstellung von hohlen, MMC und damit massereduzierten Bauteilen entwickelt, die in der Kraftfahrzeugtechnik, Wärmetechnik und Medizin sowie im Maschinenbau Anwendung finden können. Die neuen Gießverfahren beinhalten Fertigungsmethoden auf der Basis des bekannten Niederdruckgießens durch gesteuerte Formfüllung und definierte Abkühlungsbedingungen.

L’amélioration énergétique des machines électriques est un sujet de plus en plus important,avec dans la décennie à venir, l’utilisation massive de machines électriques pourles transports. Au niveau des industries, les moteurs électriques sont responsables d’environ67% de la consommation de l’énergie électrique. Ce travail de thèse s’inscrit dansl’optique de l’amélioration énergétique des machines asynchrones qui sont prépondérantesdans le milieu industriel. Le travail présenté porte sur l’utilisation de deux technologiespour augmenter le rendement avec l’utilisation combiné d’un circuit magnétique à basede tôles grains orientés (GO) et de la technologie d’une cage d’écureuil en cuivre injectésous pression. En effet, l’utilisation d’un acier plus performant comparativementaux aciers classiquement utilisés permet une réduction des pertes fer. Le remplacementde l’aluminium injecté, qui est classiquement utilisé dans la fabrication des cages d’écureuils,par du cuivre permet une réduction importante des pertes Joule au rotor. Dans unpremier temps, l’impact du processus de l’injection du cuivre en fusion sur les propriétésmagnétiques des tôles GO a été déterminé. Le processus a tout d’abord été étudié pardes simulations numériques 2D et 3D afin de déterminer les températures au niveau del’acier magnétique. Ces températures ont été appliquées sur des bandes d’Epstein pourdéterminer l’influence de celles-ci sur les propriétés magnétiques. Dans un second temps,l’utilisation des tôles GO en champ tournant a été étudiée par une méthode expérimentaleet par une modélisation numérique afin de comprendre la complexité du trajet duflux magnétique dans une telle structure de circuit magnétique. L’utilisation de cettetechnologie a permis d’obtenir un gain non négligeable en termes de pertes notammentsur les pertes fer. Dans la dernière partie, différents prototypes de machines asynchronesont été testés afin d’apprécier l’apport de ces deux technologies permettant d’apprécierun gain important en termes d’efficacité énergétique grâce à une procédure expérimentale<br>Definition of high efficiency induction machine using die casting copper squirrel cageand grain oriented steel laminations Nowadays, increasing the efficiency of electrical motorshas become a priority in order to reduce electricity consumption. This thesis dealswith the study of an induction machine composed of a copper squirrel cage realized byhigh pressure die casting and a magnetic circuit made of grain oriented electrical steel(GO) in order to decrease Joule losses and core losses. In the first part, the impact ofthermal shock induced by the die casting copper process on the GO electrical steel wasstudied in order to validate the use of GO in rotor magnetic circuit. The temperatureoccurs during this kind of process has been modeled by 2D and 3D models. An experimentalprocess was realized on the standardize samples in order to make a comparisonwith and without annealing in terms of magnetic properties. In the second part, the newassembly method of magnetic circuit with GO electrical steel has been studied in orderto increase the benefits of use of GO steel in AC machines. The last part, a comparisonbetween several configurations of magnetic circuit in induction machine was realized inorder to confirm the gain of die casting copper rotor with GO electrical steel and GOstator magnetic circuit

A key challenge facing the nuclear fusion community is how to design a reactor that will operate in environmental conditions not easily reproducible in the laboratory for materials testing. Finite element analysis (FEA), commonly used to predict components’ performance, typically uses idealised geometries. An emerging technique shown to have improved accuracy is image based finite element modelling (IBFEM). This involves converting a three dimensional image (such as from X ray tomography) into an FEA mesh. A main advantage of IBFEM is that models include micro structural and non idealised manufacturing features. The aim of this work was to investigate the thermal performance of a CFC Cu divertor monoblock, a carbon fibre composite (CFC) tile joined through its centre to a CuCrZr pipe with a Cu interlayer. As a plasma facing component located where thermal flux in the reactor is at its highest, one of its primary functions is to extract heat by active cooling. Therefore, characterisation of its thermal performance is vital. Investigation of the thermal performance of CFC Cu joining methods by laser flash analysis and X ray tomography showed a strong correlation between micro structures at the material interface and a reduction in thermal conductivity. Therefore, this problem leant itself well to be investigated further by IBFEM. However, because these high resolution models require such large numbers of elements, commercial FEA software could not be used. This served as motivation to develop parallel software capable of performing the necessary transient thermal simulations. The resultant code was shown to scale well with increasing problem sizes and a simulation with 137 million elements was successfully completed using 4096 cores. In comparison with a low resolution IBFEM and traditional FEA simulations it was demonstrated to provide additional accuracy. IBFEM was used to simulate a divertor monoblock mock up, where it was found that a region of delamination existed on the CFC Cu interface. Predictions showed that if this was aligned unfavourably it would increase thermal gradients across the component thus reducing lifespan. As this was a feature introduced in manufacturing it would not have been accounted for without IBFEM.The technique developed in this work has broad engineering applications. It could be used similarly to accurately model components in conditions unfeasible to produce in the laboratory, to assist in research and development of component manufacturing or to verify commercial components against manufacturers’ claims.

Thesis (M.F.A.)--East Tennessee State University, 2003.<br>Title from electronic submission form. ETSU ETD database URN: etd-0330103-135724. Includes bibliographical references. Also available via Internet at the UMI web site.

碩士<br>大葉大學<br>機械工程研究所碩士班<br>92<br>The polysterene pattern used in the EPC(lost-foam) mold casting mold casting will affect the quality and dimensional precision of casting after molding through its shape, dimension, and casting conditions. Therefore, it is very important to obtain the best manufacturing castings through a mold with good property and process parameters. This study is to investigate the availability of using the equipments in the conventional copper-casting factory to EPC casting, and to find the relationship between pattern shape design, manufacturing parameters, casting quality (of EPC mold by using conventional casting equipment) and the dimensional precision. also evalualed to build up the requirements in EPC method obtain which obtains the better qrality copper casting via conventional equipments. Finally, the experiments also abserve and the of EPC copper casting , and the observation shows that the imperfections on the casting surface mostly come from the gas of thermal decomposition of EPC pattein and the difficulty of gas released into sand mold due to the pattern coating.

碩士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>94<br>This research chooses the Cu54Zr22Ti18Ni6-xSix alloys to study, and uses the vacuum melting furnace to melt alloys under the argon atmosphere. The additions of silicon replace with nickel to mix the Cu-based alloys. The Cu-based bulk amorphous alloys prepared by arc melting and copper mold casting. The sample uses DSC for analysis of thermal property, uses micro-sclerometer for analysis of the mechanical property, uses XRD for the analysis of phase, and uses TEM for the analysis of microstructure. The Cu-based bulk amorphous alloys carry on the clotting time assay and valuate the hemocompatibility. The research exhibited the glass transition temperature（Tg）of the Cu-based bulk amorphous alloys at about 725K. And the Cu54Zr22Ti18Ni4Si2 amorphous alloys have the highest ΔTx at 64K. The Cu-based bulk amorphous alloys have the highest hardness at Hv 708±12 than those have the hardness at Hv 543±8 of Cu-based crystalline alloys. The Cu-based bulk amorphous alloys also have good hemocompatibility.

Underwater excavations of a Late Bronze Age shipwreck at Uluburun, Turkey recovered a combined 475 oxhide and plano-convex discoid copper ingots. While the hoard of ingots excavated at Uluburun brings the total number of copper ingots from the Late Bronze Age to over 1000, interestingly, only one ingot mold from the that period has been identified. Scholars have speculated over the means behind the creation of these ingots for decades, but with a relative absence of archaeological molds the most promising method of reaching any conclusions as to the types of molds used in antiquity seems to be experimentation. Experimental archaeology, has, in recent years been responsible for many breakthroughs in how the past is viewed. In the face of an overwhelming disparity of copper ingot molds from the Late Bronze Age, trials designed around testing different mold materials and casting techniques have the potential to determine, with relative certainty, how copper ingots were cast over 3000 years ago. This thesis examines the possible materials used to create copper ingot molds through a study of their prevalence in antiquity and also details experiments in which these materials were used, in concert with different casting techniques, to create copper ingots. The results of these experiments are combined with analyses of the Uluburun ingots in an effort to bring some closure to the debate surrounding copper ingot molds in the Late Bronze Age.

碩士<br>淡江大學<br>機械工程學系<br>86<br>This study has been utilized cast welding technique to jojnt S45C hypoeutectoid steels and copper or SK3 hypereutectoid steels and copper to become compound casting. Take those compound casting into the air furnace to heat at 760℃ for two hours, then make continuous cooling transformation of water quench, oil quench, air cooling and furnace cooling. Otherwise, at 800℃ for two hours after making marquenching, martempering and austempering of heat treatment. Discussion have any effect on microstructure of S45C hypoeutectoid compound casting and SK3 hypereutectoid compound casting during before and after the above beat treatment: 　　1.Via heat treatment of microstructure of S45C / Cu compound casting: furnace cooling are coarse pearlite and precipitation oil quench are fine pearlite, martensite and precipitation ferrite; water quench are martensite and precipitation ferrite; marquenching are quenched martensite and retained austenite; martempering are mixed - structure of tempered martemsite with lower bainite and retained austenite; austempering are upper bainite and retained austenite. 　　2.SK3 /Cu compound casting have some microstructure by way of heat treatment for example: furnace cooling are nodular cementite dispersion in ferrite matrix; air cooling are medium pearlite and oversaturation carbon compound; oil quench are fine pearlite, martensite and ferrite; water quench are martensite and oversaturation carbon compound; marquenching are quesched martensite, carbide precipitation and retained austenite; martempering are mixed - structure of tempered martensite with lower bainite and retained austenite; austempering are upper bainite, retained austenite and carbide precipitateion. 　　3.After heat treatment, We will realize S45C / Cu and SK3 / Cu compound casting will have reaction layer to yield which divides into three parts;close to iron matrix is cast welding layer (Ⅰ) , nearby copper matrix is irregular layer (Ⅱ) , and between of them is medium layer (Ⅲ). Those layer thickness had no relationship with heat treatment because utilized EPMA analysis to know most Fe atom diffused into copper matrix, only a few Cu atom diffused into iron matrix and used X - ray analysis to know interface layer elements are Fe4Cu3 and CuFeO2. For same heat treatment to understand the shear force will rise along with carbon content but interface layer elements have not relationship with carbon content directly.

# Abstract The Chalcolithic Southern Levant (4500 to 3800 BCE) is especially well-known for its outstanding copper objects, such as the crowns and mace heads, found, among others, in the Nahal Mishmar Hoard as the largest and most prominent assemblage. They are made in the lost wax casting technique with polymetallic copper alloys, whose ore sources are located in the Anatolian or Southern Caucasian mountains. The combination of this metal type, exclusively used in the Chalcolithic Southern Levant, and the earliest evidence for this technologically complex casting process in West Asia attest to a unique metallurgical development in the Chalcolithic Southern Levant. Based on promising archaeological finds, Fazael was suggested as tentative production site. This metal working tradition was paralleled by an unalloyed copper metallurgy with production sites confined to the Nahal Beer Sheva, where copper ores predominantly from Faynan were smelted and the unalloyed copper was cast in open moulds to tool-shaped objects. The major aspects of the lost wax casting process and its mould design are understood since many years from the study of mould remains attached to the metal objects and of the polymetallic copper alloys itself. However, the absence of in-situ production remains (e.g., furnaces, mould fragments) made it impossible to gather more knowledge about the operational sequence. In addition, archaeological evidence for the production and processing of the polymetallic copper alloys remains to be found; the few ore pieces with compatible chemistry in the Southeastern Anatolian sites Arslantepe and Norşuntepe were apparently not used in smelting activities. Moreover, the contrast in the preservation of production remains from the two Southern Levantine metallurgical processes seems odd, even if the lost wax casting technology is generally somewhat ephemeral. In contrast to the lost wax casting process, the unalloyed copper process can be reconstructed in more detail. Furnace remains from Abu Matar and Shiqmim indicate the use of pit furnaces, in which the ore was smelted. In a second step, the copper prills were mechanically extracted, melted in crucibles and then cast in open moulds. Nevertheless, important details remain unclear, such as the draught technique. Additionally, some aspects of the current process reconstructions seem very impracticable and thus questionable. Beside these technological aspects of the Chalcolithic metallurgy in the Southern Levant, the origin and evolution of the innovation "lost wax casting" was not investigated in detail, yet. While many studies on the cultural developments and the metallurgies in the Chalcolithic Southern Levant and the other West Asian regions exist, an inter-regional perspective was rarely taken despite the clear connection between these regions by the polymetallic copper alloys and other objects. Part of the discussion about the metallurgy of the Chalcolithic Southern Levant is also the role of the metal objects in the society and their sudden disappearance at the end of the Chalcolithic. Although several studies tackled this topic already, it remains debated, not least because the general social organisation of the Chalcolithic Southern Levant remains debated. For these reasons, this project addresses three main aims: (a) Refining the current reconstructions of the metallurgical processes in the Chalcolithic Southern Levant by combining the (re)analysis of the metallurgical assemblages from Abu Matar and Fazael with an experimental approach; (b) Tracing the evolution of the innovation "lost wax casting" in an inter-regional perspective, and (c) providing new ideas about the cultural role of the metal objects for the social system of the Chalcolithic Southern Levant. Beside the experimental and analytical work for the first part, an extensive literature review is the base for all three aims. ## Archaeological background The Chalcolithic Southern Levant is a continuation of the Late Neolithic and covered today's Israel as far South as the Northern Negev, the Westbank, and the Jordan valley. It can be subdivided in two phases, termed here Early and Late Chalcolithic. The Early Chalcolithic (4500--4300 BCE) is characterised, among others, by cornets, ceramic vessel figurines, and large architectural structures ("temples") in Gilat, En Gedi, and Teleilat Ghassul. The Late Chalcolithic (4300--3800 BCE) is characterised, among others, by the vanishing of those traits and the emergence of metallurgy. However, many aspects in the material culture remain unchanged, such as secondary burials (often ossuaries placed in caves), the lack of individually assignable burial items, stone mace heads, V-shaped bowls, and basalt bowls. Many of the metal items seem to be skeuomorphs or imitations of non-metal objects, establishing a close link between this new and the longer-used materials. Reconstructing the social organisation of the Chalcolithic Southern Levant is challenging because neither the settlements nor the burials provide clear indicators for status differences. Therefore, models of hierarchical chiefdoms exists as well as heterarchical models with heads of households. At the end, the Chalcolithic ideology and with it the entire social system seems to collapse and most of the prestige items including the lost wax cast polymetallic copper alloys disappeared with the onset of the Early Bronze Age. The Chalcolithic in the Southern Levant is a period with many innovations. Beside horticulture and the full establishment of secondary products, the slow-turning potter's wheel and metallurgy are probably the most important ones. The innovations are paralleled by a significant increase in craft specialisation with dedicated workshops for, e.g., flint tools, basalt bowls, and metal items, as well as an increase in the standardisation of pottery, especially of V-shaped bowls. Exchange was organised in a two-tiered system. A network connecting the entire region and expressed, e.g., by a uniform _chaîne opératoire_ in pottery production was overlaid by networks in the northern and southern half, characterised by perforated flint discs and unalloyed copper items plus ivories, respectively. In addition, contacts to the neighbouring cultural entities such as the Timnian in the Negev desert and to regions beyond the immediate neighbours existed. These contacts were most likely maintained by mobile parts of the population, either fully nomadic groups such as the Timnians or mobile herders from the sedentary groups. Moreover, archaeogenetic studies suggest two independent immigration waves before or during the Chalcolithic from the North. The Southeastern Anatolian and Northern Mesopotamian region splits into several groups at the end of the Ubaid (mid-5th millennium BCE), which again can be grouped by their pottery into an Eastern and a Western group, separated by the Euphrates river. At the end of the 4th millennium BCE, the Western group splits into a northern group and a southern group, and the latter orientates itself closer to the Eastern group. A unifying element of all groups is the production of chaff-faced ware and the serial production of so-called Coba bowls. While sites in the Eastern group such as Tepe Gawra have monumental architecture, a vertically stratified society, and indicators for early urbanism, similar developments are attested in the Western group with Arlsantepe as its most important site only from the mid-4th millennium BCE on. For the time under study here, no clear evidence for a stratified society can be provided in the Western group. The vertically stratified societies in the Eastern group and later in the Western group is based on staple finance, i. e. the control over the access to and distribution of resources, most importantly food. Compared to the other regions, metal items are rare in Northern Mesopotamia and Southeastern Anatolia. From the second half of the 5th millennium BCE on, apparently only small copper tools were produced and they were probably communal items. Except for three burials with small gold and silver items, burials from the period under study do not contain metal in this region. Cultural processes in the Southern Caucasus are still difficult to reconstruct. Most parts of the Sioni culture were assumingly mobile groups with too ephemeral remains to be readily recognisable in the archaeological record, and only the settlements of Mentesh Tepe and Ovçular Tepesi were investigated in detail, yet. In general, the Southern Caucasus appears to be strongly influenced by the regions to its South; chaff-faced ware is often found together with local pottery. Smelted copper is attested since the 6th millennium BCE but clear evidence for metallurgy dates only to the second half of the 5th millennium BCE. Some of the few excavated graves contained metal items. A reconstruction of the social organisation is not possible yet, but an organisation in large family groups was suggested. The situation changes markedly during the second quarter of the 4th millennium BCE. The Leilatepe-Berikldeebi culture features metal workshops and monumental architecture. In addition, the first kurgans are erected. They contain many metal and other prestige items, indicating a vertically stratified society at this time. Iran is characterised by small dispersed settlements without social stratification and minor socio-economic inequality at the end of the Neolithic. Processes during the Chalcolithic are similar in all regions but happen in a different pace. Northwestern Iran is part of the Southern Caucasus-Northern Mesopotamia cultural sphere and cultural developments follow the processes there. The North Central Iranian Plateau sees a strong increase in craft specialisation, including workshop quarters with dedicated spaces for, e.g., metallurgy and pottery. Central buildings indicate some kind of coordinating entity but there seems to be no vertical stratification of the society. Examples for long-distance exchange are moulds for shaft hole axes with the corresponding axes found in the cemetery of Susa in Southwest Iran, or lapis lazuli. Metallurgy, the two-chambered pottery kiln, and textile production in Iran is first evidenced in Southeastern Iran, from where it spreads to the other regions during the second half of the 5th millennium BCE. Apart from these innovations, this region adheres to the Neolithic settlement structure and social organisation. The Zagros Mountains seem to be populated at this time by mobile groups with large central cemeteries. Some of the burials contain metal items. In all these regions, items made of metal and exotic stones seem to be used to indicate individually assigned status. A strong contrast provides Khuzestan in Southwest Iran, where monumental architecture for public and sacral purposes in Choga Mish and Susa, and elite residences in Susa indicate a development towards a vertically stratified society. The cemeteries of Susa and Chega Sofla yielded large amounts of metal items. The finds in Chega Sofla indicate a high skill of metal working unparalleled in the other Iranian regions at this time. Southeastern Europe is included here due to the earliest evidence for copper smelting, dating to the Vinča culture (6th millennium BCE) in modern day Serbia. In the mid-5th millennium BCE this culture collapses. Settlement activities and metallurgy shifts to the Western Black Sea coast with the cemetery of Varna I being probably the most prominent site. Metallurgy in this region is characterised by a large number of heavy copper tools (more than 4300 items) and a high innovativeness with the earliest gold finds, a short episode of "natural" bronze production from stannite, evidence for the alloying of copper and gold, and lost wax casting with gold during the mid-5th millennium BCE. Similar to the Chalcolithic Southern Levant, there is no indication for social stratification in the settlements and burials, despite the large amounts of gold and copper in burials and hoards. All of these regions were in contact with each other. Archaeological evidence for contacts between the Southern Levant and its North can be traced back as early as the Natufian (13 to 9.6 ka BCE) by Anatolian obsidian in the Southern Levant. The material remains of the Wadi Rabah culture (6th millennium BCE) have many traits that can be related to the Halaf cultural sphere in the North. Similar, Tel Tsaf (first half of the 5th millennium BCE) yielded many indicators for contacts with the Ubaid cultural sphere. During the Chalcolithic, contacts are attested by, e.g., Anatolian obsidian in Southern Levantine sites. Fan scrapers indicate a technological horizon stretching from Egypt over the Southern Levant to Northern Mesopotamia. Diversity and possibly intensity of exchange increases with the Late Chalcolithic: the polymetallic copper alloys and Canaanean Blades are clearly an import from Southeastern Anatolia/Northern Mesopotamia or the Southern Caucasus, while the slow-turning potter's wheel is a Southern Levantine innovation that spread towards the North. Contacts with regions even further away are attested by, e.g., lapis lazuli beads in Southern Levantine cave sites. Moreover, strong similarities in the social organisation of Southeastern Europe and the Southern Levant were noted. Nilotic shells in Southern Levantine sites evidence contacts between the Southern Levant and Egypt. In addition, the presence of a Southern Levantine population in Egypt is evidenced by vessels manufactured from local clay in the Chalcolithic Southern Levantine pottery tradition in Buto and a subterranean house in Maadi. However, extensive exchange between Egypt and the Southern Levant is best attested in Tall Hujayrat al-Ghuzlan at the Gulf of Aqaba. This site yielded evidence for extensive copper production and shipment of copper ingots to Egypt. It is culturally unrelated to the Southern Levantine Chalcolithic. Contacts between the Southern Caucasus and the regions to its South are close since the Neolithic, as Caucasian obsidian in Anatolian sites and Halaf pottery in Caucasian sites indicate. During the period under study here, the Southern Caucasus, Northern Mesopotamia and Southeastern Anatolia are part of the chaff-faced ware technological horizon. It was suggested that differences in the material culture indicate differences between mobile highland communities with "Caucasian" material culture and lowland "Mesopotamian" settlers rather than between separate geographical regions. The emergence of the Kura-Araxes phenomenon during the first half of the 4th millennium BCE seems to be a major disruptor of the contacts between the three regions. So-called Dalma pottery attest contacts of the Southern Caucasus with Iran. In addition, shaft-hole axes were produced in both regions and their occurrence dates to roughly the same time. These axes appear already a bit earlier in Southeastern Europe and are therefore a strong indicator for contacts with this region. Southeastern Europe was also in close contact with Anatolia, albeit mostly with Western Anatolia. The distribution of ring-shaped idols indicate an exchange network spanning from Southeastern Europe to Northern Anatolia. However, the mountains between Eastern and Northern Anatolia seem to be a cultural border. Evidence for contacts with Southeastern Europe is missing in East Anatolia and, vice versa, there is no evidence for contacts with the Southern Caucasus in Northern Anatolia. ## Archaeometallurgical background The earliest known evidence for pyrometallurgy was found in Southeastern Europe, where unalloyed copper is smelted and manufactured to awls, axes, hammers and other objects since the early 5th millennium BCE. Already in the mid-5th millennium BCE, smelting activities were extensive with large amounts of heavy tools such as axes and hammers (around 4.7 t of copper in total). Compared to this huge amount of metal, the number of known smelting sites is astonishingly small. Mixtures of green and black or violet minerals were used as ore. The ores were smelted under relatively oxidising conditions in pit furnaces lined with pottery sherds, and the process yielded almost no slag. For a short period, stannite was smelted as well, resulting in tin bronze. The metal was then cast under oxidising conditions. The earliest known smelted copper in Anatolia is the large chisels, axes and needles of Mersin-Yumuktepe (around 5000 BCE), while the earliest smelting sites date only to the first half of the 5th millennium BCE. Throughout the period under study here, there is almost no change in the smelting process. Copper ore, usually weathered sulphide ore, is smelted in crucibles, which were often placed in a pit. Subsequently, the copper prills were melted in crucibles and cast in open moulds. Beside unalloyed copper, copper with elevated levels of arsenic and sometimes nickel was produced. In the Southern Caucasus, the earliest known metal finds are beads made of arsenic copper from the 6th millennium BCE. However, the earliest secure evidence for smelting activities dates only to the second half of the 5th millennium BCE. An ore pile found in Mentesh Tepe indicates the smelting of weathered copper sulphides from ophiolite-hosted ore deposits. Slag finds indicate relatively oxidising conditions. Tuyère remains from Ovçular Tepesi indicate the use of blowpipes. Furnaces are yet to be found while crucible fragments were uncovered, indicating that smelting and melting were carried out in crucibles. There is only minor change in the metallurgy of the Southern Caucasus during the period under study. The earliest evidence for copper smelting in Iran dates to the first half of the 5th millennium BCE. In Tal-i Iblis, weathered polymetallic ores were smelted in crucibles. The smelting process was more reducing than in all other regions under consideration. From early on, arsenic copper is produced alongside unalloyed copper. Larger copper items are found from the 5th millennium BCE onwards, especially in the Zagros Mountains and the neighbouring Iranian regions. Advanced casting techniques are attested by the moulds for shaft-hole axes in Tepe Ghabristan, which feature movable ceramic cores for the creation of the shaft holes. As mentioned above, the largest metal assemblages were found in Susa and Chega Sofla in Khuzestan. However, smelting sites are yet to be found in Khuzestan and it seems more probable that copper was imported from the regions further North, e.g., the North Iranian Plateau. Being one of the central topics in this study, the metallurgy of the Chalcolithic Southern Levant is extensively discussed. As already indicated, two metallurgical traditions existed: polymetallic copper alloys cast in the lost wax technique, and unalloyed copper metallurgy with open mould casting. Evidence for unalloyed copper metallurgy is confined to the Nahal Beer Sheva. The vast majority of ores was mined in Faynan and brought to the settlements for smelting. A few ore pieces were brought from Timna. Stone anvils and crushing stones with traces of copper minerals found in Abu Matar indicate the beneficiation of ores. The copper ore was directly smelted in a pit furnace of about 30 to 40 cm diameter and about 20 to 30 cm depth with a collar-shaped furnace wall of about 10 cm height. The opening in the furnace wall was about 10 cm wide. The ores were rarely fully liquefied in this furnace and the smelting products are best labelled as reacted ore rather than slag. The widespread occurrence of delafossite and cuprite indicate rather oxidising conditions, similar to the other West Asian regions except Iran. Due to the short and incomplete melting of the ore, metallic copper was present as copper prills inside the reacted ore pieces. In the next step, they were mechanically extracted, melted in crucibles and cast into objects. The crucibles are usually oval bowls with a diameter of about 10 cm and an inner depth of about 7 cm. Casting moulds are yet to be found, suggesting the use of sand moulds. Several tuyère fragments are mentioned but except one from Abu Matar no details about them are published and identification of said fragment as tyuère fragment received justified criticism. For the lost wax casting process with polymetallic copper alloys, no archaeological finds concerning the production of this metal type exists, yet. Based on the chemistry (up to 25 % Sb and 15 % As, sometimes several per cent of Pb, Ag, or Ni) antimony-rich fahl ores were suggested as ore source. Lead isotope analyses point towards the Southern Caucasus and Southeastern Anatolia as source regions. Technological investigations especially of the metal objects in the Nahal Mishmar Hoard revealed that some were cast over cores usually made of ceramic but at least in one case also stone. Further, they revealed a very heterogeneous casting quality of these objects and the occasional repair of casting errors in the cast-on technique, probably directly after the mould was removed. Mould remains adhering to the metal objects allowed to reconstruct a multi-layered mould design with at least two layers. The inner layer is often made of a paste conssiting of clay from the Moza formation, organic temper and carbonaceous sand. The outer layer is made of either ferruginous clay or lime plaster. The outcrops of suitable raw materials for the moulds suggests a location of the lost wax casting workshop(s) somewhere in the Lower Jordan valley. During the planning stage of this project, Fazael in the Middle Jordan valley was suggested as potential production site due to the co-occurrence of crucible fragments -- the first ones outside the Nahal Beer Shea sites -- and a large number of fragmented lost wax cast items in its sub-site Fazael 2. Tall Hujayrat al-Ghuzlan and Tall al-Magass at the Gulf of Aqaba revealed a proto-industrial scale of copper production with ores from Timna. These sites are not part of the Chalcolithic Southern Levant cultural sphere, as mentioned above. They differ in their copper metallurgy by the use of crucibles rather than furnaces for smelting. In addition, it seems that copper ingots were the main product at these sites while proper ingots (in contrast to metal lumps) are absent in the Chalcolithic Southern Levant. Similar to copper metallurgy, the earliest evidence for the use of gold is found in Southeastern Europe. Although not the oldest site, the cemetery of Varna I (mid-5th millennium BCE) is the most famous one because of the large number of gold items found here. Gold was manufactured into personal ornaments, ring-shaped idols, miniature tools, and staff/sceptres. Most of the objects were cast, a few in the lost wax casting technique. As a result, this site provides also the earliest evidence for this casting technology. In Western Asia, gold items occur slightly later as single small objects such a wires or beads, often in combination with items made of other exotic materials. Compared to the large spatial extent in the area, they are very rare. Important examples are the gold bead in a burial in Tepe Gawra and another one in a burial in Grai Resh, both dating towards the end of the 5th millennium BCE. About the same time date the few gold items found in Chega Sofla. A golden lost wax cast bead in Tepe Hissar dates to the first half of the 4th millennium BCE. The only gold items of the Chalcolithic Southern Levant are the two gold and six electrum rings from the Nahal Qanah burial cave. The earliest gold in the Southern Caucasus dates to the second quarter of the 4th millennium BCE, among them two massive lost wax cast bulls in the Maikop kurgan. With the gold mine in Sakdrisi and a crucible in the close-by settlement of Dzedzvebi (both mid-4th millennium BCE), this region yielded the earliest evidence for the mining and smelting of gold ore. Silver objects are reported from Southeastern European sites contemporaneous with the earliest gold finds. However, their contexts are unclear and the earliest securely datable silver items in this region date to the second half of the 4th millennium BCE. They are pre-dated by finds from Southeastern Anatolia, Northern Mesopotamia, and Iran. Silver earrings found in a burial in Hacınebi date to the first half of the 4th millennium BCE, as does the first evidence for cupellation, found in Southeastern Anatolia. From the mid-4th millennium BCE on, cupellation is attested in several sites in Northern Mesopotamia and Iran. The earliest silver finds of the Southern Caucasus were found in the kurgans, among them two silver equivalents of the golden lost wax cast bulls in the Maikop kurgan. In the Southern Levant, silver is not found before the Early Bronze Age. In addition to the archaeometallurgical background, key aspects of the smelting processes with unalloyed copper ore and fahl ores as well as the properties of polymetallic copper alloys are discussed. The draught technique, central topic in the re-assessment of the Chalcolithic unalloyed copper process in the Southern Levant, can be reconstructed from the tuyères' inner diameters. Experimental work and thermodynamic calculations showed that a diameter of 5 to 10 mm is optimal for blowpipes, while tuyères with 20 to 30 mm inner diameter are optimal for bellows. It is highlighted that with the technology and furnaces available at this time, a reducing atmosphere and a complete melting of the ore can rarely be achieved. Instead, a solid-state reaction of the copper minerals to metallic copper happened. The use of weathered sulphide ores is beneficial for the process because the exothermic reaction of sulphur with oxygen increases the temperature and the reducing atmosphere in the furnace at least locally. Experimental studies showed that smelting of (weathered) fahl ores without prior roasting can result in the production of unalloyed copper alongside speiss of a composition similar to the polymetallic copper alloys found in the Chalcolithic Southern Levant. Examples from other geographical areas showed that polymetallic alloys with such high levels of antimony and arsenic are exclusive to the Chalcolithic Southern Levant. An exception are ingots from the Bronze Age Eastern Alps. They have a comparable chemical composition but were alloyed with unalloyed copper and melted under oxidising conditions before casting the metal, significantly reducing the amount of arsenic and antimony in the cast items. All other finds with a comparable chemical composition have either less than 10 % Sb or very low arsenic levels. Arsenic, and to some extent antimony, is extremely volatile under oxidising conditions. This makes the production of arsenic copper and polymetallic alloys not straightforward. Several theoretical and experimental approaches are presented but the best method with the technological knowledge of this time seems to be the production of arsenic copper through the direct smelting of heavily weathered fahl ores or the alloying of unalloyed copper with speiss. Arsenic and antimony decrease the smelting point of copper significantly, increasing its castability. Arsenic also increases the hardness and plasticity of copper significantly, while high concentrations of antimony make copper brittle to an extent that it cannot be mechanically worked any more. Consequently, the polymetallic copper alloys used in the Chalcolithic Southern Levant could only be used for casting decorative and status-communicating items. Depending on the different levels of the alloying elements in a metal, its colour differs. For example, depending on the levels of antimony and arsenic in the copper, the colours of polymetallic copper alloys range from copper to haematite-like, golden, and silver-like colours. The different colours of metal alloys was not only used by past metallurgists as indicator for the composition of the metals but was also deliberately exploited for aesthetic purposes, e.g., by the arrangement of differently coloured gold beads in a necklace in the Varna I cemetery. C. S. Smith concluded that aesthetic properties of new materials were always exploited before their usability for tools. Metal is not different from other materials in this regard. Consequently, the role of metal objects in past societies should be investigated as one material under many and not as superior to e.g. pottery or stone. The early metal items in Southeastern Europe are good examples for such a focus on the sensory properties of metals. They were embedded in an aesthetic concept of shininess together with graphitised pottery. It seems that the occurrence of many different metal types with different shiny colours (e.g. silver) over the 4th millennium BCE in Western Asia was motivated by the same pursuit for shiny materials. The example of the South American Muisca show that it is not necessarily the metal items that are of importance, but it can also be the production process (in this case lost wax casting) as the focal point of a ritual. ## Lost wax casting ### Visibility in the archaeological record Despite the large number of Chalcolithic sites in the Southern Levant, all mould remains so far were found attached to metal objects in protected places such as burial caves. As a result, it remains unclear whether mould remains at the production sites are not preserved, were found but not recognised as such or are yet to be found. Although previous studies identified a multi-layered design, the use of chaff temper, and the occasional use of plaster as key characteristics of the moulds, most of these features can only be recognised with petrographical methods and not readily in the field. Therefore, an archaeological experiment was carried out based on knowledge from previous studies and complemented by ethnographical records to investigate the recognisability of lost wax casting moulds in the archaeological record. Because layers made of different clays can be easily identified in thin sections, the recognisability of layers with the same clay but with different amounts and proportions of temper was investigated. The archaeological experiment was a multi-purpose experiment. Raw materials comparable to the materials used in the Chalcolithic were used to re-create the lost wax casting moulds. The moulds were then heated to remove the wax. At the same time, crucibles and a furnace were built according to the reconstructed furnaces of the unalloyed copper process to test their operability with bellows (see below) and to melt the copper and antimony for casting. Four runs were carried out, in none of them was enough metal melted for a successful casting. The moulds were fragile right after casting and their fragility increased significantly in the next couple of days. Complete cross-sections of two moulds as well as partial sections of the other moulds were prepared for petrographic examination. Recorded trampling and submerging experiments with mould pieces and other metallurgical ceramics were carried out to simulate mechanical stress and their interaction with water. Because none of the archaeological moulds showed interaction with the molten metal and the archaeological and experimental ceramic pastes are overall comparable, the experimental moulds are viable analogues of the archaeological ones. The post-experiment increase in the fragility of the moulds is best explained by the rehydration of the carbonaceous sand after heating and the associated volume increase. Crushing the moulds and sectioning them for petrography revealed that the inner and outer layer can be easily separated, masking their original multi-layered design. Petrographic analyses showed that the different layers can only be recognised by the different temper mixtures of the clay pastes. The alteration tests revealed that the mould fragments are stable when submerged for several hours but that one step is often enough to crush them into tiny crumbs, which are not recognisable in the archaeological record any more. Consequently, mould remains in archaeological sites must be expected to be rare. If preserved, they are friable and potentially rounded pieces of low-fired ceramics and, therefore, might be easily mistaken for heated soil crumbs. An additional universally applicable characteristic of the lost wax casting moulds is suggested: the mixture of vegetal and mineral temper. The validity of this criterion is underpinned by general technological considerations. Pottery in the Late Chalcolithic Southern Levant is made exclusively with mineral temper, and metallurgical ceramics exclusively with chaff temper. In case of pottery, this temper choice maximises mechanical strength and reduces porosity of the vessels. For metallurgical ceramics, a high porosity is desirable to increase heat insulation and to prevent spreading of cracks. Lost wax casting moulds had to combine both properties: The comparably thick moulds had to be stable enough to be heated from the outside to sufficient temperatures inside. At the same time, the high porosity especially in the inner layer prevents the spreading of cracks while allowing the air in the mould to escape during casting. With this criterion at hand, mould fragments can be reliably identified regardless of their multi-layered design, as long as archaeologists are aware to collect seemingly inconspicuous pieces of heated sediment or low-fired ceramics. ### The meallurgical assemblage of Fazael Fazael is located along the riverbank of the Wadi Fazael and consists of several Chalcolithic broad room houses and other archaeological features. Excavations in the broad room house Fazael 2 yielded many fragments of lost-wax cast and unalloyed copper items together with several crucible fragments and heated sediment nodules and, thus, was suggested to having been a lost wax casting site. Metallurgical installations such as furnaces are yet to be found, though. The broad room Fazael 5 yielded a small hoard, consisting of a head-shape standard into which a chisel, an awl and a spiral-shaped object were shoved. The broad house Fazael 7 has walls preserved to a height of more than 1 m and contained many metal fragments as well as complete metal items. Fazael 2 was radiocarbon dated to 4000 to 3900 BCE, i.e. to the very end of the Southern Levantine Chalcolithic. This date is supported by an incomplete Chalcolithic material culture and the appearance of elements typical for the Early Bronze Age, such as Canaanean Blades. Due to the already fragmented state of the many metal objects, a representative selection of them could be sectioned for metallographical investigation including SEM-EDX. In addition, several crucible fragments and heated sediment nodules were sectioned for petrography. The aim was to investigate whether the remains allow an identification of Fazael 2 as lost wax casting site and to gather new insights into the lost wax casting process. The chemical composition of the sampled metal objects is in agreement with previous analyses from other sites, although the polymetallic copper alloys have an overall slightly depleted arsenic concentration and are slightly enriched in the other alloying elements. The items can be subdivided into three groups based on their metallographic structure: unalloyed copper objects, objects with low levels of alloying elements and objects with high levels of alloying elements. These groups correspond to the chemical composition of the objects. They confirm existing notions of the Chalcolithic metallurgy but add two important observations: the metal of some items contain large amounts of silt-sized angular quartz, and some of the polymetallic copper alloys contain inclusions of unalloyed copper and, in one case, of a multi-phase copper alloy. The copper inclusions show that the polymetallic copper alloys were not completely melted upon casting. While a reliable estimate of the actual melting temperature is impossible due to the complex interplay of the alloying elements, all of them decrease the melting point of the alloys compared to unalloyed copper. Consequently, the metal could be liquid enough for casting well below the melting point of unalloyed copper. At the same time, the presence of unalloyed copper inclusions in the polymetallic copper alloys evidence some sort of mixing of the two metal types. In addition, the inclusions of multi-phase copper alloys in one sample indicate that such mixing must not necessarily involve only unalloyed copper. This is the first evidence for mixing of polymetallic copper alloys. The motivation for and location of the mixing action remains unknown. It could be related to, e.g., the alloying of speiss as some sort of master alloy with unalloyed copper or recycling. The whereabouts of the quartz inclusions must remain unknown as well. In contrast to a single sample from Bir es-Safadi, they occur in the entire section and not only at the surface. This excludes their origin as contamination from, e.g., the casting mould. Options are presented but none of them could provide a convincing hypothesis why silt-sized quartz is dispersed throughout the object. The crucible fragments can be separated into three petrographic groups. The first group does not consist of crucibles but vessel fragments made of Moza clay. The second group consists of the low-fired object F225a with a calcareous foraminifera-rich clay and carbonaceous sand. Only the third group contains actual crucibles as is indicated by the vitreous and bloated ceramic paste with vegetal matter, in good agreement with the metallurgical ceramics from the Nahal Beer Sheva sites. The heated sediment nodules seem to be made from the same clay as the crucibles but were heated to much lower temperatures. While some of them contain no temper at all, other contain vegetal temper, carbonaceous sand, or both. One nodule features two layers of different size fractions of the same clay. F2-Y55 is distinct from all these nodules because it is entirely blackened and contains rounded inclusions of vitreous copper-free material, together with vegetal and mineral temper. Comparison with sediments from the Wadi Fazael showed that crucibles and heated sediment nodules were made of this clay. According to the criteria established above, most of the heated sediment nodules can be reliably interpreted as remains of lost wax casting moulds. Being a single find, the function of F225a must remain unclear. In conclusion, the study of the metallurgical assemblage of Fazael allowed identifying Fazael as production site for lost wax cast objects by the identification of in-situ lost wax casting mould fragments for the first time. In addition, it provided for the first time direct evidence for the mixing of polymetallic alloys with unalloyed copper and tentatively also with other polymetallic alloys. ## Re-assessing the metallurgical assemblage of Abu Matar Based on the experience from past smelting experiments, some aspects of the current reconstruction of the Chalcolithic unalloyed copper process in the Southern Levant seemed impractical, particularly the use of blowpipes through the collar opening, and covering the furnace with a large ceramic lid, as suggested by J. M. Golden. In an attempt to refine this reconstruction, the metallurgical ceramics and slag of the Abu Matar excavations in the 1990s were re-assessed and led to the identification of several important but hitherto overlooked pieces. The probably most important ones are two pieces with a clear channel-like feature of about 2.5 to 3.0 cm diameter. While one is made of chaff-tempered ceramic and only slightly vitrified with some greenish spots, the other is completely vitrified. In addition, a large slag fragment features a similar channel with a larger diameter. Further, several ceramic objects are particularly thick, rounded on one side and have slagged sides that extent over the edge to another side. Two other ceramic rim fragments deviate visibly in their paste from the other metallurgical ceramics by the presence of carbonaceous sand and the absence of chaff temper. The slags and some of the ceramics were sampled for microscopic and SEM-EDX analyses. For the remaining objects, the macroscopic features were of interest and sampling did not promised any additional insights. Results of the analyses show that the sand-tempered ceramics are secondarily used fragments of a V-shaped bowl and a hole-mouth jar. While secondary use of V-shaped bowls as crucibles was already previously encountered, this is the first evidence for the secondary use of other vessel types in the metallurgical process. The slagged fracture on one side of the hole-mouth jar fragment suggest the use of hole-mouth jar sherds as furnace cover. Such a use would also allow to cover the furnace with objects that are much easier to handle than one large ceramic lid. The completely vitrified fragment with the channel-like feature turned out to be of ceramic origin rather than slag. Together with the other ceramic fragment with a channel-like feature, they are interpreted as tuyère fragments due to the lack of other objects in the metallurgical process with such a narrow channel. Their diameters suggest the use of bellows. Operating the furnace with bellows instead of blowpipes through the collar opening appears much more sensible because it allows heating of a larger area in the furnace while operating the furnace more efficiently with less effort. In addition, the archaeological experiment showed that a bellows-operated furnace can produce sufficiently high temperatures for copper smelting. A reconstruction for the use of the rounded ceramic fragments was not entirely possible. They do not appear to be part of the furnace wall nor do other sites report any comparable objects. It is suggested here that they may have been some kind of mobile platform for the crucibles to melt the copper prills next to the mould, and fragments of the "clay cakes" J. Perrot mentioned but described only poorly. Based on these results and interpretations, the reconstruction of the unalloyed copper process can be refined: Smelting of copper ore in a furnace covered with hole-mouth jar fragments to keep the heat and to increase the reducing conditions. Bellows were used for draught. The furnace was operated in a rotating manner, placing fresh fuel and ore on the side opposite the tuyère and pushing it closer to the tuyère when the material there reacted. The copper prills were then mechanically extracted from the slag as previously reconstructed and then melted in crucibles. Because handling of the crucibles inside the pit furnace is difficult, they were most likely placed on small mobile platforms next to the moulds, where they were covered in small heaps of fuel. Probably, blowpipes provided draught for this step because they allow much more control over the intensity and direction of the air stream. ## Evolution of the innovation "lost wax casting" Based on the extensive literature review, a large West Asian interaction sphere consisting of Southeastern Anatolia, Northern Mesopotamia, the Southern Caucasus and Iran can be reconstructed. Within this interaction sphere, materials but also ideas could spread quite easily but were not necessarily adopted everywhere. Moreover, two fundamentally different status-communicating systems could be identified. The Southern Levant, parts of Iran, and Southeastern Europe communicated status through metal objects and other so-called prestige items. A characteristic of this system is the use of metal items and other exclusive goods as burial goods. In contrast, Northern Mesopotamia and other parts of Iran used monumental architecture and staple finance to communicate status. The status-communicating system of the Southern Caucasus is unclear but the absence of monumental architecture and the presence of metal items in some of the burials suggest it belongs to the former one. On another strand, except for the Southern Levant, lost wax cast items in West Asia at this time are always made of gold and massively cast. It is therefore suggested that a technological package "lost wax casting with gold" spread from Southeastern Europe through the Caucasus into the West Asian interaction sphere, probably together with the shaft hole axes. Depending on the compatibility with the status-communicating system, this technological package was modified. While the shaft hole axes were readily adopted in the Southern Caucasus and Iran, the technological package becomes only visible in the archaeological record after some delay, seemingly unchanged but in the very different ideological setting of a vertically stratified society. In Northern Mesopotamia and Southeastern Anatolia, only the new material gold seems to be adopted. An explanation might be that the ideological aspects of the technological package -- communicating status through metal objects -- was incompatible with the communication of status through staple finance and monumental architecture while gold as new material was compatible to the newly discovered silver. The Southern Levant adopted and heavily modified the technological package. Instead of gold, polymetallic copper alloys were used, the produced objects are much larger than anything else produced in this technique before, and ceramic cores were used instead of massive casts. The reasons for these modifications seem to be technological and aesthetic. Gold is not readily available in the Southern Levant and the large amounts necessary for the produced objects probably exceeded by far, what was available elsewhere -- if it was available there. In addition, polymetallic copper alloys have a much lower melting point and it seems likely that it was only because of this that such large objects could be produced in the lost wax casting technique. The aesthetic component was probably equally important: Depending on the composition of the polymetallic copper alloys, not only the new materials gold and silver could be imitated but also haematite. Haematite mace heads were produced long before the advent of metallurgy in the Chalcolithic Southern Levant and vessel figurines, ossuaries and other ceramic objects often decorated with red bands. Ceramic cores were likely used to save on metal. A key factor for this quick adoption in the Chalcolithic Southern Levant is the compatibility of the technological package with the existing social system. It is argued here that metal items in the Chalcolithic Southern Levant are representations of objects made of other materials (e.g., stone, pottery, wood). The arrival of metallurgy in general and the lost wax casting technology in particular did not only fill a need in the local population for such shiny representations. At the same time, the strong modification of the technological packages makes it likely that it was stripped from its ideological aspects except for the most basic concepts, status-communication through special items and use of shiny materials, and fully included into the local ideology. ## Role of metal in the Chalcolithic Southern Levant Previous research already indicated that both, the unalloyed copper objects and the lost wax cast objects were status-communicating items. Therefore, their role in the Chalcolithic Southern Levant must be discussed together. Rather than a full-fledged hypothesis, some ideas are presented. It is suggested that all copper-based metal objects in the Chalcolithic Southern Levant are representations (skeuomorphs, imitations) of objects made of other materials. While this is rather obvious for tool-shaped objects and mace heads, other objects were likely made of perishable materials. For example, previous studies suggested that the decorated mace heads might represent seeds or bulbs and some objects in the Nahal Mishmar Hoard have similarity with reed canes. If the ideology of the Chalcolithic Southern Levant is so heavily ritualised as suggested by some researchers, the metal objects are likely to be ritual representations of mundane objects. However, some iconic objects of the Chalcolithic Southern Levant do not have metallic representations, such as V-shaped bowls and basalt bowls. A likely explanation is that they were already ritual objects and, therefore, did not need metallic representations. The turn of the Early to the Late Chalcolithic and the associated change from architecture to metal items for status display might indicate a shift in the ritual system of the Chalcolithic Southern Levant. It is suggested that this shift might be related to a decline of the Chalcolithic ideology due to a decreased power in explaining the changing environment. Metal objects might have been the opportunity to reinforce this power. It is further suggested that one of the key elements to understand the role of metals in the Chalcolithic Southern Levant is their colour. We know from other cultures that gold is often associated with the sun, while silver is associated with the moon. Both were important divine entities in early farming societies. In the Chalcolithic ideology, haematite-like colours or red in general might be related to the ancestors. Thus, metallurgical practices might have been a way to connect with the divine sphere and transform objects from the mundane sphere into the ritual sphere. Smelting and melting can be easily turned into audio-visually impressive rituals, through which this communication could be performed. Previous studies suggested that many aspects of the Chalcolithic ideology are related to a cycle of death and rebirth. Metallurgy was probably firmly embedded in it. Smelting haematite-rich copper ore to metal might symbolise the rebirth of ancestors. Transforming items symbolising them into their metallic equivalents might have been part of rituals connected to the passage of deceased into the nether world. If they were indeed symbolic representations of the deceased, the central aspect of metallurgy might have been the ritual transformation of the mundane item into its ritualised representation. This must not necessarily be connected to metallurgical processes, i.e. their production. This could explain why metal items were part of exchange networks together with other ritual objects. At the end of the Chalcolithic, the ideology collapses entirely and most of the prestige-items disappear. Environmental conditions probably changed to an extent that the Chalcolithic ideology could not provide suitable explanations for them anymore, leading to ritual failure. In addition, internal conflicts might have originated from the important ritual role of metal and might have contributed to the decline of the ritual framework of the Chalcolithic ideology. With the collapse of the Chalcolithic ideology, the lost wax cast items and the polymetallic alloys lose their purpose, whereas the utilitarian value of unalloyed copper was recognised, perhaps inspired from the Aqaba sites. Consequently, the lost wax casting metallurgy was abandoned while the unalloyed copper metallurgy was incorporated into the efficiency-focussed and goal-oriented mindset of the Early Bronze Age.

碩士<br>國立高雄科技大學<br>模具工程系<br>107<br>The study investigates the causes of the different casting and hot rolling conditions on different edge crack to slab casting of C2680 copper alloy. Different manufacturing process factors might cause C2680 copper alloy to have crack on the two sides of copper coil when it is calendaring. Therefore, the current study focuses on decreasing hot rolling edge crack with orthogonal arrays designed by Taguchi method (L934) and with four control factors brainstormed by the researcher. A: casting speed, B: the amount of cooling water, C: the heating temperature before hot rolling, D: the frequency of hot rolling. Then, the researcher set up the standards to do a crossover trial. Nine research analysis; each group being tested for three times; ninety final products for each test. The control factors of S/N ratio were calculated from by analyzing the research results with the smaller is better of S/N ratio. From such result, the researcher explored the level of influence of the control factor on and the most efficient group condition from the control factors on C2680 copper alloy hot rolling edge crack. Last, the researcher used ANOVA analysis to examine the F-test & Q-test and reliability of research results. The results show that the most efficient group condition from the control factors is “casting speed is 120 mm/min ; the amount of cooling water is 170 m3/hr ; the heating temperature before hot rolling is 850℃ ; the frequency of hot rolling is 21 times. The degree of influence & contribution of the control factor on the cracking of the hot rolling forming in decreasing order are the frequency of hot rolling > casting speed > the amount of cooling water > the heating temperature before hot rolling.

Задорожній В. С. Аналіз технології вогневого рафінування міді : кваліфікаційна робота магістра спеціальності 136 "Металургія" / наук. керівник Р. М. Воляр. Запоріжжя : ЗНУ, 2020. 79 с.<br>UA : Виконано аналіз технології вогневого рафінування міді та вплив умов кристалізації мідних анодів у виливниці на їх якість. Виконано порівняльний аналіз лиття анодів в умовах зміни градієнта температури який впливає на структури і зернистість мідних анодів. Встановлено технологічні режими що сприяють утворенню дрібнокристалічної структури, яка легко розчиняється в сірчанокислому розчині при електролітичному рафінуванні міді, та сприяє підвищення виходу катодів.<br>EN : The analysis of the technology of fire refining of copper and the influence of the conditions of crystallization of copper anodes in molds on their quality is carried out. A comparative analysis of the casting of anodes under the conditions of a change in the temperature gradient, which affects the structure and grain size of copper anodes, is carried out. Technological modes have been established that promote the formation of a fine-crystalline structure, which is easily dissolved in a sulfuric acid solution during the electrolytic refining of copper and contributes to an increase in the yield of cathodes.

L’objet de la présente étude est le développement, l’application et la diffusion de la technologie associée à divers types d’alliages de cuivre, en particulier l’alliage du plomb-bronze, en Grèce ancienne, dans ses colonies, ainsi qu’en Étrurie. Le plomb-bronze est un mélange de diverses proportions d’étain, de cuivre et de plomb. Le consensus général chez les archéométallurgistes est que le plomb-bronze n’était pas communément utilisé en Grèce avant la période hellénistique; par conséquent, cet alliage a reçu très peu d’attention dans les documents d’archéologie. Cependant, les analyses métallographiques ont prouvé que les objets composés de plomb ajouté au bronze ont connu une distribution étendue. Ces analyses ont aussi permis de différencier la composition des alliages utilisés dans la fabrication de divers types de bronzes, une preuve tangible que les métallurgistes faisaient la distinction entre les propriétés du bronze d’étain et celles du plomb-bronze. La connaissance de leurs différentes caractéristiques de travail permettait aux travailleurs du bronze de choisir, dans bien des cas, l’alliage approprié pour une utilisation particulière. L’influence des pratiques métallurgiques du Proche-Orient a produit des variations tant dans les formes artistiques que dans les compositions des alliages de bronze grecs durant les périodes géométrique tardive et orientalisante. L’utilisation du plomb-bronze dans des types particuliers d’objets coulés montre une tendance à la hausse à partir de la période orientalisante, culminant dans la période hellénistique tardive, lorsque le bronze à teneur élevée en plomb est devenu un alliage commun. La présente étude analyse les données métallographiques de la catégorie des objets coulés en bronze et en plomb-bronze. Elle démontre que, bien que l’utilisation du plomb-bronze n’était pas aussi commune que celle du bronze d’étain, il s’agissait néanmoins d’un mélange important d’anciennes pratiques métallurgiques. Les ères couvertes sont comprises entre les périodes géométrique et hellénistique.<br>The subject of this study is the development, application and diffusion of the technology of various types of copper alloys, particularly that of leaded bronze, in ancient Greece, its colonies, and in Etruria. Leaded bronze is a mixture of tin, copper and lead in various proportions. The general consensus among archaeometallurgists is that leaded bronze was not commonly used in Greece until the Hellenistic period, and thus this alloy has not received very much attention in archaeological literature. However, metallographic analyses demonstrate that objects composed of leaded bronze had a wide distribution. The analyses also show differentiation in the composition of alloys that were used in the manufacture of various types of bronzes, a tangible indication that metalworkers distinguished between the properties of both tin bronze and leaded bronze. The knowledge of their different working characteristics is what enabled a bronzeworker to choose, in many cases, the appropriate alloy for a specific application. The influence of Near Eastern metallurgical practices produced variations in both the artistic forms as well as alloy compositions of Greek bronzes during the Late Geometric and Orientalizing periods. The use of leaded bronze for particular types of cast objects shows an increasing tendency from the Orientalizing period onwards, culminating in the late Hellenistic period when high-lead bronze became a common alloy. This study analyzes the metallographic data of specific categories of bronze and leaded bronze cast objects, and it will demonstrate that although the use of leaded bronze was not as prevalent as that of tin bronze, it was nevertheless a significant adjunct of ancient metallurgical practices. The periods surveyed range from the Geometric to the Hellenistic periods.