We are proudly a Ukrainian website. Our country was attacked by Russian Armed Forces on Feb. 24, 2022.
You can support the Ukrainian Army by following the link: https://u24.gov.ua/.
Even the smallest donation is hugely appreciated!
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Consulte a lista de atuais artigos, livros, teses, anais de congressos e outras fontes científicas relevantes para o tema "Powder deposition".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Zowarka, R. C., J. R. Uglum, J. L. Bacon, M. D. Driga, R. L. Sledge e D. G. Davis. "Electromagnetic powder deposition experiments". IEEE Transactions on Magnetics 35, n.º 1 (1999): 268–73. http://dx.doi.org/10.1109/20.738415.
Van der Schueren, B., e J. P. Kruth. "Powder deposition in selective metal powder sintering". Rapid Prototyping Journal 1, n.º 3 (setembro de 1995): 23–31. http://dx.doi.org/10.1108/13552549510094241.
Mihara, Kensuke, Takuya Hoshina, Hirofumi Kakemoto, Hiroaki Takeda e Takaaki Tsurumi. "Effects of Pretreatments on Deposition Rate of Films in Aerosol Deposition Method". Key Engineering Materials 421-422 (dezembro de 2009): 165–68. http://dx.doi.org/10.4028/www.scientific.net/kem.421-422.165.
In the aerosol deposition method (ADM), we investigated an influence of pre-treatments for barium titanate powders as raw material on the deposition rate of thick films. By sieving and drying the powder, deposition rate of the films fabricated by ADM was effectively enhanced. On the other hand, heating the powders at 400-800°C, the resulting powders caused low deposition rate of the films. When a planetary milling was performed prior to charge aerosol chamber, the deposition rate of the films was four times higher than that in deposition using the powder without milling. By changing the milling rotation rate, we control size of agglomerated particles consisting of powders, which results in the control of deposition rate of the films.
5
Svetlizky, David, Honorata Kazimierczak, Bar Ovadia, Ariel Sharoni e Noam Eliaz. "Electrochemical Processing and Thermal Properties of Functional Core/Multi-Shell ZnAl/Ni/NiP Microparticles". Materials 14, n.º 4 (9 de fevereiro de 2021): 834. http://dx.doi.org/10.3390/ma14040834.
Electroless deposition on zinc and its alloys is challenging because of the negative standard potential of zinc, the formation of poor surface layers during oxidation in aqueous solutions, and extensive hydrogen evolution. Therefore, there are only few reports of electroless deposition on Zn and its alloys, neither of them on micro/nano powders. Here, we propose a two-step process that allows the formation of compact, uniform, and conformal Ni/NiP shell on Zn-based alloy microparticles without agglomeration. The process utilizes controlled galvanic displacement of Ni deposition in ethanol-based bath, followed by NiP autocatalytic deposition in an alkaline aqueous solution. The mechanism and effect of deposition conditions on the shell formation are discussed. Thermal stability and functional analysis of core-shell powder reveal a thermal storage capability of 98.5% with an encapsulation ratio of 66.5%. No significant morphological change of the core-shell powder and no apparent leakage of the ZnAl alloy through the Ni shell are evident following differential scanning calorimetry tests. Our two-step process paves the way to utilize electroless deposition for depositing metallic-based functional coatings on Zn-based bulk and powder materials.
6
Yan, Lei, Xueyang Chen, Wei Li, Joseph Newkirk e Frank Liou. "Direct laser deposition of Ti-6Al-4V from elemental powder blends". Rapid Prototyping Journal 22, n.º 5 (15 de agosto de 2016): 810–16. http://dx.doi.org/10.1108/rpj-10-2015-0140.
Purpose This paper aims to achieve Ti-6Al-4V from Ti, Al and V elemental powder blends using direct laser deposition (DLD) and to understand the effects of laser transverse speed and laser power on the initial fabrication of deposit’s microstructure and Vickers hardness. Design/methodology/approach Two sets of powder blends with different weight percentage ratio for three elemental powder were used during DLD process. Five experiments with different processing parameters were performed to evaluate how microstructure and Vickers hardness change with laser power and laser transverse speed. Energy dispersive X-ray spectroscopy, optical microscopy and Vickers hardness test were used to analyze deposits’ properties. Findings This paper reveals that significant variance of elemental powder’s size and density would cause lack of weight percentage of certain elements in final part and using multiple coaxial powder nozzles design would be a solution. Also, higher laser power or slower laser transverse speed tend to benefit the formation of finer microstructures and increase Vickers hardness. Originality/value This paper demonstrates a new method to fabricate Ti-6Al-4V and gives out a possible weight percentage ratio 87:7:6 for Ti:Al:V at powder blends during DLD process. The relationship between microstructure and Vickers hardness with laser power and laser transverse speed would provide valuable reference for people working on tailoring material properties using elemental powder method.
7
Yu, Minjae, Yuji Ichikawa e Kazuhiro Ogawa. "Development of Cu Coating on Ceramic Substrates by Low Pressure Cold Spray and its Deposition Mechanism Analysis". Materials Science Forum 1016 (janeiro de 2021): 1703–9. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.1703.
Cold spray (CS) is a solid-state deposition technique of micron-sized metallic powder in an ultra-high velocity gas using a de Laval nozzle. CS is a unique deposition technique due to its use of relatively lower gas temperatures in comparison to other thermal processes. Consequently, high-temperature oxidation and phase transformations of deposited powders are largely restricted while the operating cost of CS is much lower than that of other thermal processes. Generally, the low pressure cold spray (LPCS) technique is used for the deposition of metallic powders on metallic substrates, while only a few studies of metallic particle deposition on ceramic substrates have been conducted, and it was found that the deposition of metallic powders on ceramic substrates was quite difficult. In this study, improved LPCS deposition of copper coatings on zirconia substrates was investigated. It is known that deposition of a metallic powder on a ceramic substrate is difficult due to the differences in material bonding and several properties of the two materials. These difficulties in LPCS deposition were solved using three different approaches, namely 1) use of copper and aluminum composite powders and 2) laser pre-treatment and 3) laser texturing of zirconia substrates. It was found that pure copper powder coatings on the as-received and various treated substrates were delaminated in the interface as expected. However, the deposition was improved for all substrates by using the copper and aluminum composite powder. While the laser pre-treated substrate was not effective for the deposition of the copper and aluminum composite powder, thick coatings were obtained for the deposition on the laser pre-treated with heat treatment substrate and the laser-textured substrate.
8
Yoshihara, Nobuhito, Ryoko Hiromatsu, Koichi Mizutani, Ji Wang Yan e Tsunemoto Kuriyagawa. "Laser Assist Powder Jet Deposition". Advanced Materials Research 126-128 (agosto de 2010): 58–63. http://dx.doi.org/10.4028/www.scientific.net/amr.126-128.58.
Amorphous NiP plate is used as a mold of precision optical parts owing to the superior machinability. In the amorphous NiP plate, some pores, whose diameter is about 100m, are generated occasionally. At present, the amorphous NiP plates with pore are rejected. However, because size of the mold becomes large in recent years, the possibility of pores becomes high. In addition, the cost of the amorphous NiP plate also becomes high. Therefore, reparation method of the pore in the amorphous NiP plate should be developed. In this paper, laser assist powder jet deposition is proposed as a reparation method of the amorphous NiP plate. And fundamental experiments are carried out.
9
Anisimov, Alexander G., Victor V. Zykov e Gennady A. Shvetsov. "Electromagnetic Launcher for Powder Deposition". IEEE Transactions on Plasma Science 39, n.º 1 (janeiro de 2011): 9–12. http://dx.doi.org/10.1109/tps.2010.2087365.
Siva Prasad, Himani, Frank Brueckner e Alexander F. H. Kaplan. "Powder incorporation and spatter formation in high deposition rate blown powder directed energy deposition". Additive Manufacturing 35 (outubro de 2020): 101413. http://dx.doi.org/10.1016/j.addma.2020.101413.
Teses / dissertações sobre o assunto "Powder deposition":
1
Addison, Julian Alston. "The electrostatic deposition of powder coatings". Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388929.
Pitcairn, Gary Roy. "The scintigraphic assessment of drug delivery from dry powder inhalers". Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363603.
Lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) are major health burdens on the global population. To treat diseases of the lung, topical therapies using dry powder inhalers (DPIs) have been employed. However, a relatively small amount of dose (5.5 - 28 %) reaches the lung during DPI therapy leading to high inter-patient variability in therapy response and oropharyngeal deposition. Strategies were assessed to take patient variability in inhalation performance into account when developing devices to reduce throat deposition and to mitigate flow rate dependency of the emitted aerosol. A cyclone-spacer was manufactured and evaluated with marketed and in-house manufactured formulations. An in vivo study showed that a high resistance inhaler would produce longer inhalation times in lung disease patients and that a spacer with high resistance may prove a suitable approach to address inter-patient variability. Two spacer prototypes were evaluated with cohesively- and adhesively-balanced particle blends. The data suggested that the throat deposition dramatically decreased for the emitted particles when the spacers were used with the inhalers (e.g. 18.44 ± 2.79% for salbutamol sulphate, SS 4 kPa) due to high retention of the formulation within the spacer (87.61 ± 2.96%). Moreover, variation in fine particle fraction and dose was mitigated when increasing the flow rate (82.75 ± 7.34 %, 92.2 ± 7.7 % % and 77.0 ± 10.1 % at 30, 45 and 60 Lmin-1, respectively). The latter was an improvement over previous proposed DPI spacers, where variability in emitted dose due to airflow rate was a major issue. Due to the different physicochemical properties of the active pharmaceutical ingredients used in the formulation, throat deposition and respirable fraction for adhesively-balanced particles (e.g. SS) were double that of the cohesively- balanced particles (salmeterol xinafoate, SX) (e.g. 65.83 ± 8.99 % vs. 45.83 ± 5.04 % for SS:Coarse Lactose (CL) and SX:CL, respectively). Scanning electron microscopy revealed that surface-bound agglomerates were more freely removed from the carrier, but subject to decreased impaction-type deagglomeration forces in the spacer than for carrier-bound drug. An ex vivo study using breath profiles from healthy volunteers identified the minimization of differences between adhesively- and cohesively-balanced blends when full breath profiles were studied compared to square-wave airflow. Therefore the use of constant flow for in vitro testing should not be the sole flow regime to study aerosolization when developing new inhalation devices and formulations.
4
Syed, Waheed Ul Haq. "Combined wire and powder deposition for laser direct metal additive manufacturing". Thesis, University of Manchester, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.556499.
Heywood, Benjamin. "The design and manufacture of a powder deposition system for a large powder bed on a three dimensional printer". Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/11163.
Konrad, Chad E. "Analysis of heat transfer in subcooled metal powder subjected to pulsed laser heating". Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4300.
Thesis (M.S.)--University of Missouri-Columbia, 2005. The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 14, 2006) Includes bibliographical references.
7
Leazer, Jeremy D. "Processing-microstructure-property relationships for cold spray powder deposition of Al-Cu alloys". Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45887.
Approved for public release; distribution is unlimited This thesis presents research on the cold gas-dynamic spray process applied to the deposition of aluminum-copper alloy coatings. Cold spray deposition is a process utilized to create corrosion protection coatings and to perform additive repair for aluminum structures. This thesis utilized a series of Al-Cu binary alloy powders, from 2–5 weight percent copper and characterized their chemistry and microstructure. The powders were deposited using the cold spray approach to study the systematic increase of the alloying agent on the deposition process and coating characteristics. Deposition efficiency, critical velocity, coating thickness, hardness, porosity, and microstructure were all characterized as functions of carrier gas pressure, carrier gas temperature and feedstock powder copper composition. This thesis has demonstrated that all of the aluminum copper powders utilized can be successfully deposited via the low-pressure cold spray process with helium as the carrier gas. The copper content of the powders has a direct effect on the volume fraction of Al2Cu intermetallics, and on the coating hardness, while having no measurable effect on critical velocity for deposition or the coating thickness per pass.
8
Markusson, Lisa. "Powder Characterization for Additive Manufacturing Processes". Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62683.
The aim of this master thesis project was to statistically correlate various powder characteristics to the quality of additively manufactured parts. An additional goal of this project was to find a potential second source supplier of powder for GKN Aerospace Sweden in Trollhättan. Five Inconel® alloy 718 powders from four individual powder suppliers have been analyzed in this project regarding powder characteristics such as: morphology, porosity, size distribution, flowability and bulk properties. One powder out of the five, Powder C, is currently used in production at GKN and functions as a reference. The five powders were additively manufactured by the process of laser metal deposition according to a pre-programmed model utilized at GKN Aerospace Sweden in Trollhättan. Five plates were produced per powder and each cut to obtain three area sections to analyze, giving a total of fifteen area sections per powder. The quality of deposited parts was assessed by means of their porosity content, powder efficiency, geometry and microstructure. The final step was to statistically evaluate the results through the analysis methods of Analysis of Variance (ANOVA) and simple linear regression with the software Minitab. The method of ANOVA found a statistical significant difference between the five powders regarding their experimental results. This made it possible to compare the five powders against each other. Statistical correlations by simple linear regression analysis were found between various powder characteristics and quality of deposited part. This led to the conclusion that GKN should consider additions to current powder material specification by powder characteristics such as: particle morphology, powder porosity and flowability measurements by a rheometer. One powder was found to have the potential of becoming a second source supplier to GKN, namely Powder A. Powder A had overall good powder properties such as smooth and spherical particles, high particle density at 99,94% and good flowability. The deposited parts with Powder A also showed the lowest amount of pores compared to Powder C, a total of 78 in all five plates, and sufficient powder efficiency at 81,6%.
9
Deceuster, Andrew Isaac. "Investigation of Joining Micro-Foil Materials with Selective Laser Sintering and Laser Powder Deposition". DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/434.
Continuous and pulse selective laser sintering and laser powder deposition were used to find a solution to the manufacturing of micro-foil lattice structured components. A full factorial test matrix was used for each process to determine the processes capability to produce continuous tracks for joining the micro-foil materials. The samples were evaluated for dimensional profiles, distortion, and cycle times, to develop selection criteria for implementation of the processes into industry. The selective laser sintering processes were able to join the micro-foil materials into lattice structures with continuous tracks. The laser powder deposition processes were not able to properly join the micro-foil materials into lattice structures. The end results showed that micro-foil lattice structures can be produced using continuous and pulse selective laser sintering.
10
Audronis, Martynas. "Deposition and characterization of boron-based coatings by sputtering from loosely-packed powder targets". Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444248.
International Conference on Metal Powder Deposition for Rapid Manufacturing (2002 San Antonio, Tex.). Metal powder deposition for rapid manufacturing: Proceedings of the 2002 International Conference on Metal Powder Deposition for Rapid Manufacturing sponsored by the Metal Powder Industries Federation in cooperation with the Laser Institute of America (LIA) and APMI International. Princeton, NJ: Metal Powder Industries Federation, 2002.
A, Johnson Edward. Depositional history of Triassic rocks in the area of the Powder River Basin, northeastern Wyoming, and southeastern Montana. Washington, D.C: U.S. G.P.O., 1993.
Brown, Janet L. Sedimentology and depositional history of the Lower Paleocene Tullock Member of the Fort Union Formation, Powder River Basin, Wyoming and Montana. [Washington]: U.S. G.P.O., 1993.
Flores, Romeo M. After a century: Revised Paleogene coal stratigraphy, correlation, and deposition, Powder River Basin, Wyoming and Montana. Reston, Va: U.S. Dept. of Interior, U.S. Geological Survey, 2010.
A, Moody John. Erosion and deposition of sediment at channel cross sections on Powder River between Moorhead and Broadus, Montana, 1980-98. Denver, Colo: U.S. Geological Survey, U.S. Dept. of the Interior, 2002.
Johnson, Edward A. Depositional history of Jurassic rocks in the area of the Powder River Basin, northeastern Wyoming and southeastern Montana. Washington: U.S. G.P.O., 1992.
Seeland, David A. Depositional systems of a synorogenic continental deposit: The Upper Paleocene and Lower Eocene Wasatch Formation of the Powder River Basin, northeast Wyoming. [Washington, D.C.]: U.S. G.P.O., 1992.
Dogan, Ahmet Umran. Stratigraphy, petrology, depositional and post-depositional histories and their effects upon reservoir propertiesof the Parkman Formation of the Mesaverde Group, Powder River Basin, Wyoming. Ann Arbor, Mich: UMI Dissertation Inf. Service, 1987.
Orban, Radu L., Mariana Lucaci, Mario Rosso e Marco Actis Grande. "NiAl Behavior at Plasma Spray Deposition". In Progress in Powder Metallurgy, 1545–48. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-419-7.1545.
Grünenwald, B., W. Hennig, St Nowotny, F. Dausinger e H. Hügel. "Laser Process Adapted Powder Delivery System". In Laser Processing: Surface Treatment and Film Deposition, 411–20. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0197-1_20.
Cho, Kwon Koo, Kyo Hong Choi, Ki Won Kim, Gyu Bong Cho e Yoo Young Kim. "Characterization of GaP Nanowires Synthesized by Chemical Vapor Deposition". In Progress in Powder Metallurgy, 25–28. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-419-7.25.
Olevsky, Eugene A., e Xuan Wang. "Graded Powder Composites by Freeze Drying, Electrophoretic Deposition and Sintering". In Progress in Powder Metallurgy, 1533–36. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-419-7.1533.
Kim, J., Y. C. Choi, Hyoung Seop Kim e Sun Ig Hong. "Biomimetic Deposition of Apatite on Zr-1Nb and Ti-6Al-4V". In Progress in Powder Metallurgy, 1013–16. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-419-7.1013.
Lee, Jae Ho, e Gun Ho Chang. "Non-Electrolytic Deposition of Silver on Tungsten Powders for Functionally Gradient Composite Powder". In Progress in Powder Metallurgy, 1469–72. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-419-7.1469.
Mayr, Helmar, Marc Ordung e Günter Ziegler. "EPD of a Sub Micron HA Powder for Biomedical Applications". In Electrophoretic Deposition: Fundamentals and Applications II, 225–30. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-998-9.225.
Trabalhos de conferências sobre o assunto "Powder deposition":
1
Bacon, J. L., D. G. Davis, R. J. Polizzi, R. L. Sledge, J. R. Uglum e R. C. Zowarka. "A New Electromagnetic Powder Deposition System". In ITSC 1997, editado por C. C. Berndt. ASM International, 1997. http://dx.doi.org/10.31399/asm.cp.itsc1997p0393.
Abstract Existing state of the art thermal spray processes (HVOF, D-Gun, Plasma Spraying) are limited to powder velocities of about 1 km/sec because they rely on the thermodynamic expansion of gases. A new thermal spray process using electromagnetic forces can accelerate powder particles to a final velocity of up to 2 km/sec. At this velocity powder particles have sufficient kinetic energy to melt their own mass and an equivalent substrate mass on impact. The process is based on railgun technology developed by the Department of Defense. A railgun is filled with argon gas and a high energy electrical pulse, provided by a capacitor bank, drives the gas down the railgun to a final velocity of up to 4 km/sec. This gas passes over a powder cloud and accelerates the powder through drag forces. The electrical and powder discharge frequency can be adjusted so that the deposition rate and thermal input to the substrate can be controlled.
2
Langerman, Michael A., Gregory A. Buck, Umesh A. Korde e Vojislav D. Kalanovic. "Thermal Control of Laser Powder Deposition: Heat Transfer Considerations". In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60386.
Laser based solid free-form fabrication is an emerging metallurgical forming process aimed at rapid production of high quality, near net shape products directly from starting powders. Laser powder deposition shares, with other free-form technologies, the common characteristic that part fabrication occurs directly from a 3-D computer aided design (CAD) model. The microstructure evolution and resulting material properties of the component part (strength, ductility, etc.) fabricated using laser deposition are dependent upon process operating parameters such as melt pool size, laser power, head (manipulator) speed, and powder flow rate. Presently, set points for these parameters are often determined through manual manipulation of the system control and trial and error. This paper discusses the development of a path-planning, feed-forward, process-driven control system algorithm that generates a component part thermal history within given constraints, thereby assuring optimal part quality and minimizing final residual stresses. A thermal model of the deposition process drives the control algorithm. The development of the thermal model is the subject of this paper. The model accounts for temperature-dependent properties and phase change processes. Model validation studies are presented including comparisons with known analytic solutions as well as comparisons with data from experiments conducted in the laser laboratory at SDSM&T.
3
Uglum, J. R., J. L. Bacon, D. G. Davis, R. J. Polizzi, R. L. Sledge e R. C. Zowarka. "Scaling Analysis of the Electromagnetic Powder Deposition (EPD) Gun". In ITSC 1997, editado por C. C. Berndt. ASM International, 1997. http://dx.doi.org/10.31399/asm.cp.itsc1997p0385.
Abstract The electromagnetic powder deposition (EPD) system employs high velocity gas flow to accelerate powder material to conditions required for high strength plating. The gas flow, however, is not continuous; rather it consists of bursts generated by an electromagnetic railgun and pulsed power system. Each gas burst is created by a high pressure plasma arc which fills a transverse section of the gun. This current carrying arc is driven by the railgun Lorentz force (magnetic pressure) and acts much like a piston, which via a snowplow process accelerates and compresses an ambient gas column to the flow speed required to accelerate powder particles. Analysis of the total system was carried out to provide scaling relations which give guidance in design of the system. Plating considerations define a desired powder velocity; this combined with the choice of working gas and ambient pressure determines the velocity and duration of each gas burst. Selection of gun geometry completes the definition of the pulsed power system requirements. An outline of the analysis is presented along with the physical models used.
4
Schanwald, L. Paul. "Two powder stream diagnostics for laser deposition processes". In ICALEO® ‘95: Proceedings of the Laser Materials Processing Conference. Laser Institute of America, 1995. http://dx.doi.org/10.2351/1.5058967.
Anshakov, A. S., A. I. Aliferov, A. E. Urbach e E. K. Urbach. "Arc plasma generator for deposition of powder coatings". In 2008 Third International Forum on Strategic Technologies (IFOST). IEEE, 2008. http://dx.doi.org/10.1109/ifost.2008.4602844.
Sledge, R. L., J. L. Bacon, D. G. Davis, R. J. Polizzi, J. R. Uglum e R. C. Zowarka. "Arc Initiation for the Electromagnetic Powder Deposition Gun". In ITSC 1997, editado por C. C. Berndt. ASM International, 1997. http://dx.doi.org/10.31399/asm.cp.itsc1997p0377.
Abstract The Electromagnetic Powder Deposition (EPD) process converts pulsed electrical energy into kinetic and thermal energy to accelerate and heat powder material to conditions suitable for bonding. A high pressure plasma armature is electromagnetically accelerated using a railgun. A supersonic pressure wave is created when the armature accelerates through and "snowplows" the ambient gas ahead of it. The gas column is heated, compressed, and accelerated to the entrainment section of the gun, where some of the thermal and kinetic energy is transferred to an injected stream of powder material. The acceleration burst is repeated rapidly to supply the required deposition rate and to achieve steady thermal conditions. Development of a starter plasma which is reliable at ambient pressure was a major programmatic task. Generation of a low pressure linear arc required to form a planar armature during the pulsed event was investigated. Several geometries (point-to-point breakdown, rail-to-rail breakdown, and confined glow discharge) were explored using different voltage sources (dc, 60 Hz ac, 150 MHz rf, pulsed). Satisfactory operation of the confined glow discharge approach at atmospheric pressure was achieved using rf excitation. Results of testing under the various scenarios are presented and critiqued.
7
Perez, Lorena, Jake Colburn, Luke N. Brewer, Michael Renfro e Tim McKechnie. "Cold Spray Deposition of Heat-Treated Inconel 718 Powders". In ITSC2021, editado por F. Azarmi, X. Chen, J. Cizek, C. Cojocaru, B. Jodoin, H. Koivuluoto, Y. C. Lau et al. ASM International, 2021. http://dx.doi.org/10.31399/asm.cp.itsc2021p0171.
Abstract In this work; Inconel 718 gas-atomized powder was successfully heat treated over the range of 700-900°C. As-atomized and as-heat treated powders were cold sprayed with both nitrogen and helium gasses. Cold spray of high strength materials is still challenging due to their resistance to particle deformation affecting the resulting deposit properties. Powder heat treatment to modify its deformation behavior has recently been developed for aluminum alloy powders; however; there is no literature reported for Inconel 718 powders. The microstructural evolution of the powder induced by the heat treatment was studied and correlated with their deformation behavior during the cold spray deposition. Deposits sprayed with heat-treated powders at 800 and 900 °C and nitrogen showed less particle deformation and higher porosity as compare to as-atomized deposit associated to the presence of delta phase in the powders precipitated by the heat treatment. In contrast; deposits sprayed with helium using both powder conditions; as-atomized and as heat-treated powders; showed high particle deformation and low porosity indicating that the type of gas has a greater effect on the particle deformation than the delta phase precipitated in the heat-treated powders. These results contribute to understanding the role of powder microstructure evolution induced by heat treatment on the cold spray deposits properties.
8
Wang, Wei, Andrew J. Pinkerton e Lin Li. "A gas-free powder delivery system for 100% deposition efficiency in direct laser deposition". In ICALEO® 2008: 27th International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing. Laser Institute of America, 2008. http://dx.doi.org/10.2351/1.5061341.
Xiang, Sen, e Huan Qi. "A camera based control method of deposition bead width in laser powder deposition process". In ICALEO® 2014: 33rd International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing. Laser Institute of America, 2014. http://dx.doi.org/10.2351/1.5063127.
Bourne, Keith A., Parisa Farahmand e David Roberson. "Simulation of Cross-Sectional Geometry During Laser Powder Deposition of Tall Thin-Walled and Thick-Walled Features". In ASME 2016 11th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/msec2016-8623.
A model of the laser powder deposition (LPD) process is presented, which predicts the cross-sectional geometry of parts that are made up of thin-walled and thick-walled features, deposited via multiple passes. The model builds up the part shape incrementally by predicting the cross-section of a bead of material deposited on the part, updating part shape to reflect the added material, and repeating for each additional deposition pass. The effects of laser power and deposition speed are accounted for empirically, and the effect of nozzle stand-off distance is accounted for via a powder catchment model suitable for coaxial deposition nozzles. The model was calibrated via deposition experiments using stainless steel 316L powder and via measurement of nozzle characteristics. Validation tests showed that the powder catchment model captured the effect of nozzle stand-off distance on deposited bead size. Validation tests also showed that the model predicted the overall shapes of both thin-walled and thick-walled features, including rounding present at the edges of some thick-walled features. Using calibration data from short thick-walled depositions, the average error in predicted feature height, after ten layers, was 9.3% and 9.5% for thin-walled and thick-walled features, respectively. The model was also shown to predict the effects of using a step-up distance per layer that is too small, resulting in inefficient deposition, or too large, resulting in deposition failure after a few layers.
Relatórios de organizações sobre o assunto "Powder deposition":
1
Troksa, M. Vibration Assisted Powder Deposition. Office of Scientific and Technical Information (OSTI), setembro de 2019. http://dx.doi.org/10.2172/1561451.
Raghavan, Narendran, Brian H. Jordan e Ryan R. Dehoff. Controlling microstructure in deposits fabricated using powder blown direct energy deposition technique. Office of Scientific and Technical Information (OSTI), junho de 2018. http://dx.doi.org/10.2172/1459282.
Herbold, E. B., O. Walton e M. A. Homel. Simulation of Powder Layer Deposition in Additive Manufacturing Processes Using the Discrete Element Method. Office of Scientific and Technical Information (OSTI), outubro de 2015. http://dx.doi.org/10.2172/1239200.
Brown, R. D. Power deposition measurements at the LAMPF Neutron Radiation Effects Facility. Office of Scientific and Technical Information (OSTI), junho de 1985. http://dx.doi.org/10.2172/5523498.
Fraser, Hamish L., e James C. Williams. Metallurgical Factors Influencing Direct Laser Deposition of Metallic Powers for Unitized Structures. Fort Belvoir, VA: Defense Technical Information Center, janeiro de 2005. http://dx.doi.org/10.21236/ada435779.
B. LeBlanc, C.K. Phillips, G. Schilling, G. Taylor, J.R. Wilson e et al. Electron Power Deposition Measurements During Ion Cyclotron Range of Frequency Heating on C-Mod. Office of Scientific and Technical Information (OSTI), maio de 1999. http://dx.doi.org/10.2172/6714.
Talghader, Joseph J. High Power Optical Coatings by Atomic Layer Deposition and Signatures of Laser-Induced Damage. Fort Belvoir, VA: Defense Technical Information Center, agosto de 2012. http://dx.doi.org/10.21236/ada564804.
Don W. Miller. An In-Core Power Deposition and Fuel Thermal Environmental Monitor for Long-Lived Reactor Cores. Office of Scientific and Technical Information (OSTI), setembro de 2004. http://dx.doi.org/10.2172/832911.
Kevin Crist. Evaluation of the Emission, Transport, and Deposition of Mercury and Fine Particulate Matter from Coal-Based Power Plants in the Ohio River Valley Region. Office of Scientific and Technical Information (OSTI), dezembro de 2008. http://dx.doi.org/10.2172/1015450.
Kevin Crist. Evaluation of the Emission, Transport, and Deposition of Mercury, Fine Particulate Matter, and Arsenic from Coal-Based Power Plants in the Ohio River Valley Region. Office of Scientific and Technical Information (OSTI), abril de 2006. http://dx.doi.org/10.2172/891303.
