To see the other types of publications on this topic, follow the link: Metal castings Solidification.
Journal articles on the topic 'Metal castings Solidification'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Metal castings Solidification.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Zhengwuvi, L. B., and A. O. Akii Ibhadode. "Risering of a Four-Cavity Die Production Mould by Convectional Method." Advanced Materials Research 62-64 (February 2009): 664–70. http://dx.doi.org/10.4028/www.scientific.net/amr.62-64.664.
Full textAbstract:
This paper demonstrates the possibility of developing skill in producing sound metal casting from a four-cavity die production mould by assessing the riser design criteria and the castings. The assessment takes into account the location of the casting’s hot spots, casting modulus, liquid metal mass in the risers and the principle of directional solidification. The mould flask is oriented in such a way that a riser is placed directly on top of the casting’s hot spots for proper feeding during solidification. The assessment result of casting modulus shows that the feeder modulus Mf = 5.85 x 10-3 M and the casting hot spot modulus Mh = 1.88 x 10-3 M .The assessment result of castings solidification time shows that the castings solidify within 12 seconds while the feeders solidify within 30 seconds. From the assessment results it is observed that the risers hold liquid metal, feed the castings to full solidification and solidify later than the castings which they feed. Examinations at the cross sections of the finished castings revealed the absence of void formation which is a clear indication of effective and functional risers. Thus, the risers have achieved the desired requirement.
2
Prikhod’ko, O. G., V. B. Deev, E. S. Prusov, and A. I. Kutsenko. "Influence of thermophysical characteristics of alloy and mold material on castings solidification rate." Izvestiya. Ferrous Metallurgy 63, no. 5 (July 1, 2020): 327–34. http://dx.doi.org/10.17073/0368-0797-2020-5-327-334.
Full textAbstract:
Obtaining castings of given quality is the main task of foundry production. One of the stages of casting technology is solidification of melt in the mold. When studying the process of castings solidification, it is necessary to fully take into account all the features of heat transfer between casting and mold. Influence of various thermophysical parameters of alloy and mold material on casting formation is considered. In the analysis, original mathematical models were used to calculate the coefficient and time of complete solidification of castings in sand-clay and metal forms. These models take into account geometric parameters of casting, main thermophysical parameters of casting metal and mold material, heat transfer conditions at crystallization front, on casting-mold boundary and on the mold surface. Analysis of dependence of time and rate of castings solidification on thermophysical parameters (heat capacity, density, heat conductivity of casting material and mold, specific heat of metal crystallization) was carried out. Storage capacity and process of heat storage are quite fully characterized by the value of heat storage coefficient. This coefficient practically determines the rate of heat loss by the casting which plays a decisive role in its properties forming. Therefore, this parameter is selected for a comprehensive analysis of thermal processes occurring in casting and mold. The influence of thickness and thermal conductivity of chill paint layer on solidification of castings in metal molds is considered. The basic calculation formulas and initial data are presented. Calculations were carried out for castings of the following types: endless plate, endless cylinder, ball. The results of simulation of solidification process parameters are presented in graphic form. Using various alloys as an example, it has been shown by calculation that when changing composition and properties of mold material, it is possible to change time and speed of alloys solidification in a wide range. In this case, processes of forming the structure and properties of castings are controlled.
3
Rvachev, V. L., T. I. Sheiko, V. Shapiro, and J. J. Uicker. "Implicit Function Modeling of Solidification in Metal Castings." Journal of Mechanical Design 119, no. 4 (December 1, 1997): 466–73. http://dx.doi.org/10.1115/1.2826391.
Full textAbstract:
Solidification of metal castings can be modeled by an implicit real-valued function whose behavior is determined by physical parameters prescribed on the boundary of a casting. We show how to construct such functions using theory of R-functions for two-dimensional castings represented by their boundaries. The parameterized form of the constructed functions is convenient for studying, controlling, and optimizing their behavior in terms of the physical parameters specified on the boundary of the casting. The proposed approach can also be used for modeling multiple cavities in a same sand mold, generalizes to three-dimensional castings, and is applicable to other physical phenomena that may be suitable for analysis based on empirical knowledge.
4
Fecko, D., I. Vasková, Ľ. Eperješi, and M. Závodný. "Usage of Connor Inlets to Eliminate Shrinkage." Archives of Foundry Engineering 12, no. 3 (September 1, 2012): 25–28. http://dx.doi.org/10.2478/v10266-012-0076-0.
Full textAbstract:
Abstract The demand for castings of high quality and sound work is nowadays very high. The production of sound castings without foundry errors is the big issue in modern foundries. Foundry simulation software can do a lot to help improve the disposition of castings, gating system and feeder system, and assure good filling and solidification conditions, and also produce sound casting without the need of the old method of "try and error". One can easily change a lot of parameters for filling and solidification, and create the best proposal for production. Connor inlets have two functions. One is that it serves as an ingate, through which molten metal passes and comes into the mould cavity. The second function is that it serves as a feeder and substitutes the metal contracted during solidification and cooling of the castings. It can also save quite a lot of metal in comparison to classic feeders.
5
Maekawa, Tatsuya, Mitsuaki Furui, Susumu Ikeno, Tomoyasu Yamaguchi, and Seiji Saikawa. "Microstructure Observation of AM60 Magnesium Alloy Solidified by Rapidly Quench." Advanced Materials Research 409 (November 2011): 339–42. http://dx.doi.org/10.4028/www.scientific.net/amr.409.339.
Full textAbstract:
In solidification theory, with a slow cooling rate such as sand mold casting, it is easy to segregate the solute aluminum near the grain boundary of primary α-Mg phase under the solidification in Mg-Al system alloys. Thus, volume fraction of none-equilibrium crystallized β-Mg17Al12 phase showed the higher value compared with metal mold casting with faster cooling rate. However, in our microstructure observation results, the volume fraction of β phase in permanent mold castings was larger than that of sand mold castings. In the present study, these contradictory behavior was investigated by observation of as-solidified microstructure obtained from rapid cooling castings at the just below the solidus temperature of 723, 773 and 823K.
6
Madhan Kumar, P., Elizabeth Jacob, S. Savithri, and G. S. Suneeth. "Quantitative Feeder Design for Metal Castings." Materials Science Forum 830-831 (September 2015): 49–52. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.49.
Full textAbstract:
Casting simulation packages are used to check a design for its castability. A better starting design should need fewer simulation cycles to arrive at a defect-free component thus cutting computation and manpower costs. Quantitative design of the feeding system is done by an analysis of the solidification pattern of the 3D model of the cast component. A clustering algorithm uses the solidification time/temperature data from the simulation to divide the casting into 3D feeding sections. The sections are created by following hotspots surrounded by areas of decreasing solidification time. Feeders are built by the feeder design module of AutoCAST casting design software. The initial simulation as well as the efficacy of the rigging is tested through the advanced simulation module FLOW+ of AutoCAST X. An industrial case study illustrates the software pipeline in a virtual foundry trial.
7
Suresh, N., and P. Chandrasekar. "Microstructure and Mechanical Properties of Castings under Vibration Techniques - A Review." Applied Mechanics and Materials 550 (May 2014): 71–80. http://dx.doi.org/10.4028/www.scientific.net/amm.550.71.
Full textAbstract:
The challenging problems for designers and engineers in the material science are to enhance the quality of the castings. The several numbers of methods using external forces have been applied to introduce fluid flow during solidification of molten metal in casting process. These include mechanical, electromagnetic and ultrasonic vibration. Many technical journals describe the improvement in mechanical properties of castings under the vibration during solidification. In this paper, an attempt has been made to review the casting process to refine the microstructure of cast product. The awareness gain of these processes and application of the procedures offer the scope for better cost savings in design and manufacturing of cast products.
8
Domeij, Björn, and Attila Diószegi. "Solidification Chronology of the Metal Matrix and a Study of Conditions for Micropore Formation in Cast Irons Using EPMA and FTA." Materials Science Forum 925 (June 2018): 436–43. http://dx.doi.org/10.4028/www.scientific.net/msf.925.436.
Full textAbstract:
Microsegregation is intimately coupled with solidification, the development of microstructure, and involved in the formation of various casting defects. This paper demonstrates how the local composition of the metal matrix of graphitic cast irons, measured using quantitative electron microprobe analysis, can be used to determine its solidification chronology. The method is applied in combination with Fourier thermal analysis to investigate the formation of micropores in cast irons with varying proportions of compacted and spheroidal graphite produced by remelting. The results indicate that micropores formed at mass fractions of solid between 0.77 and 0.91, which corresponded to a stage of solidification when the temperature decline of the castings was large and increasing. In 4 out of the 5 castings, pores appear to have formed soon after the rate of solidification and heat dissipation had reached their maximum and were decreasing. While the freezing point depression due to build-up of microsegregation and the transition from compacted to spheroidal type growth of the eutectic both influencing solidification kinetics and the temperature evolution of the casting, the results did not indicate a clear relation to the observed late deceleration of solidification.
9
Teng, Hai Tao, Bai Qing Xiong, Yon Gan Zhang, and Ting Ju Li. "Investigation on Sub-Rapid Solidification Behavior of Semi-Solid Magnesium Alloy Metal." Advanced Materials Research 320 (August 2011): 156–62. http://dx.doi.org/10.4028/www.scientific.net/amr.320.156.
Full textAbstract:
In order to investigate sub-rapid solidification behavior of semi-solid magnesium alloy metal, a novel semi-solid processing technique, called new vacuum suction casting (NVSC), is used to manufacture thin castings of AZ91D Mg-alloy directly from a liquid metal. The resulting microstructures of castings are characterized in detail and linked to the solidification behavior. In the microstructure of the sub-rapidly solidified SSM sheet, the “preexisting” primary solid particles, with the morphology of near-globules or rosettes, disperse in the homogeneous matrix consisting of fine near-equiaxed secondary α-Mg grains and fine precipitates of β-Mg17Al12 intermetallics. Owing to rapid solidification rate, the volume fraction of the β phase in the sub-rapidly solidified SSM sheets is much lower than that in the as-cast ingot. In addition, the content of alloying elements of Al and Zn was higher in the grain boundaries and the eutectic structure than that in the primary solid particles and in the second α-grains.
10
Sturm, Jörg C., and Wilfried Schäfer. ""Cast Iron - A Predictable Material” 25 Years of Modeling the Manufacture, Structures and Properties of Cast Iron." Materials Science Forum 925 (June 2018): 451–64. http://dx.doi.org/10.4028/www.scientific.net/msf.925.451.
Full textAbstract:
During the last 25 years, casting process simulation has developed from predicting hot spots and solidification paths to an integral assessment and optimization tool for foundries for the entire manufacturing route of castings. Modeling cast irons has always been a special challenge due to the strong interdependency between the alloy composition, applied metallurgy and metal treatment with the solidification, phases and structures which form and the resulting properties of the material.
11
Suranuntchai, Surasak, and Ekkachai Kittikhewtraweeserd. "Analysis of Horizontal Squeeze Casting Process for Pipe Oil Part." Advanced Materials Research 482-484 (February 2012): 154–58. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.154.
Full textAbstract:
To achieve the laminar flow filling pattern in squeeze casting processes, many literatures [1-4] have reported that ideal velocity of liquid metal passing through the ingate should be between 0.1 – 0.5 m/sec. John Campbell [1] reported that liquid metal front speed velocity should be 0.4 m/sec in order to eliminate the gas porosity inside the casting. However, such slow speed requires the higher temperature of liquid metal and die. This results in not only the longer cycle time but also a coarser microstructure of the casting. In addition, the sample castings used in the literature are simple form castings which do not reflect the real castings used in daily life. In this study, the indirect squeeze casting processes is adopted to cast a motorcycle’s component originally produced by a high pressure die casting process. Based on shape and dimensions of the casting to get the real casting out for the mass production, melt’s speed must be higher than the level reported by the literatures (around 1 m/sec). As a result, a fully laminar flow may not be achievable. This is confirmed by the primary study of the process parameters and tooling design using the casting process simulation. However, by clinging on the two principles of the squeeze casting processes; (1) minimizing the amount of entrapped air by slowly fill the cavity and (2) reducing the amount of solidification shrinkage by pressurized solidification; the casting from two processes will be casted in order to compared the micro-structure and mechanical properties.
12
Pastirčák, Richard, Ján Ščury, and Tomáš Fecura. "Heat flow and heat transfer coefficient during crystallization under the pressure." MATEC Web of Conferences 157 (2018): 02036. http://dx.doi.org/10.1051/matecconf/201815702036.
Full textAbstract:
Estimation of the heat flow at the metal-mold interface is necessary for accurate simulation of the solidification processes. For the numerical simulation, a precise prediction of boundary conditions is required to determine the temperature distribution during solidification, porosity nucleation, microstructure development, and residual stresses. Determination of the heat transfer coefficients at the metal-mold interface is a critical aspect for simulation of the solidification process and the microstructure modeling of the castings. For crystallization under the pressure and for thin-walled castings, HTC evaluation is important due to the very limited freezing time.
13
Gao, Cun Zhen, Di Xin Yang, Jing Pei Xie, Ai Qin Wang, and Wen Yan Wang. "Casting Process Optimization for Large Bearing Bush of Zinc-Base Alloy." Materials Science Forum 704-705 (December 2011): 40–44. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.40.
Full textAbstract:
The numerical simulation of temperature gradient in the solidification process for large bushing castings of zinc-base alloy was made with HUAZHU CAE/Inte-CAST10.0 software in this paper. Tendency and the position of shrinkage were predicted,and the effect of cooling water rate and cooling time on temperature gradient and shrinkage during the molten metal solidification was discussed. The results show that:seting chilled iron at bottom of bearing bush and using water-cooling metal core in inner cavity of casting simultaneously, can eliminated shrinkage hole and porosity.
14
Nadolski, M., Z. Konopka, M. Łągiewka, and A. Zyska. "The Influence of the Method of Mould Filling on the Quality of Castings Made of EN AC-44000 or EN AC-46200 Alloy." Archives of Foundry Engineering 14, no. 4 (December 1, 2014): 73–76. http://dx.doi.org/10.2478/afe-2014-0089.
Full textAbstract:
Abstract The performed examinations concerning the process of filling the plaster ceramic moulds with aluminium alloys allowed to assess the influence of various methods of introducing the metal into the mould cavity on the macro- and microstructure of the obtained experimental castings. The comparison was performed for castings with graded wall thickness made either of EN AC-44000 alloy or of EN AC-46000 alloy, produced either by gravity casting, or by gravity casting with negative pressure generated around the mould (according to the Vacumetal technology), or by counter-gravity casting. It was found that the silicon crystals grow in size with an increase in wall thickness due to the slower cooling and solidification of castings
15
Bobba, Sujith, Sambasiva Rao Mukkollu, Z. Leman, and Harish Babu Bachina. "Experimental Investigation on the Effect Due to Mould Vibrations on Mechanical and Metallurgical Properties of Aluminum Alloy (A-1050)." International Journal of Surface Engineering and Interdisciplinary Materials Science 9, no. 1 (January 2021): 77–86. http://dx.doi.org/10.4018/ijseims.2021010105.
Full textAbstract:
In the current research work performed, the consequences caused in the casting aluminum alloy specimen due to mechanical mould vibrations are examined. Mould vibration throughout the casting provides decreased rate of shrinkage, good morphology, surface finish and lesser probability of hot tear. In this research work, the effect of mould vibration during solidification of Aluminum A-1050 alloys for dissimilar values of wavelengths at a permanent pouring temperature has been investigated to understand the modification in microstructure and mechanical properties after casting. The Al A-1050 casting has been made in a metal mould with different vibrations. The frequencies are varied from 15Hz to 50 Hz during the casting process. A casting has been made with different vibration as well to compare the results of castings with vibration frequencies. The experimental outcomes exhibited substantial grain refinement and significant increase in tensile strength and hardness of the castings with mechanical mould vibration during the duration and after solidification.
16
Liu, Gang, Lin Liu, Guo Jun Zhang, and Jun Zhang. "Microstructure and Element Segregation of Ni-Base Superalloy Casting with Radiation and Liquid-Metal Cooling." Materials Science Forum 816 (April 2015): 608–12. http://dx.doi.org/10.4028/www.scientific.net/msf.816.608.
Full textAbstract:
A Re-containing single-crystal superalloy was processed with conventional radiation high rate solidification (HRS) and liquid-metal cooling (LMC) techniques, respectively. Compared with the HRS castings, LMC castings exhibited the greatly refined dendrite structures and lower segregation. At the withdrawal rate of 50 μm/s, the primary and secondary dendrite arm spacing of LMC casting was 103 and 19 μm, which were reduced by 60 % and 53 % compared to the counterpart of HRS castings. Moreover, higher withdrawal rates significantly shortened the characteristic diffusion distance and reduced the residual segregation of refractory elements after homogenization-solution treatments, which is beneficial for improving the local phase stability of Re-containing superalloys.
17
Kumar, Vinod, and Amitesh Kumar. "Simulation of Cooling Rate of Gray Cast Iron Casting in a Sand Mold and its Experimental Validation." Materials Science Forum 710 (January 2012): 208–13. http://dx.doi.org/10.4028/www.scientific.net/msf.710.208.
Full textAbstract:
Estimation of cooling rates of gray cast iron casting in the sand mold and its dependency on design and process parameters is one of the keys for achieving best processing conditions to produce quality castings. The estimation of cooling rate involves modeling of fluid flow, heat transfer and solidification of molten metal inside the mold. Prediction of heat transfer has been carried out from filling of mold but the estimation of cooling rate has been carried out after complete filling of the mold. In the present work fluid flow, heat transfer and solidification of molten metal in a sand mold model has been developed on a Pro-Cast 2008 platform. A stepped bar pattern with different thickness has been fabricated to carry out the experiment. Stepped bar pattern has been selected because gray cast iron castings are thickness sensitive as well as different section of castings have different cooling rate. Cooling rates have been determined experimentally by measuring the Dendritic Arm Spacing (DAS) and Secondary Dendritic Arm Spacing (SDAS) from the microstructure of different steps. Results show that the morphology of graphite, dendritic arm spacing and secondary dendritic arm spacing as well as the interlamellar spacing of eutectic structure depend on the casting thickness. These decreases as the thickness of castings decrease because thinner section of casting has higher rate of cooling than the thicker section. The estimated cooling rate matched well with the experimentally measured cooling rate.
18
Anjos, Vitor, Carlos A. Silva Ribeiro, Fátima Dias, Wolfgang Baumgart, and João Cunha. "Literature Survey on Porosity and Microporosity in Cast Irons Related to Expansion and Gas Entrapment Phenomena." Key Engineering Materials 457 (December 2010): 410–15. http://dx.doi.org/10.4028/www.scientific.net/kem.457.410.
Full textAbstract:
Macro and microporosity in castings are a problem that persists at many foundries, despite the use of advance simulation software’s. This fact indicates that other parameters rather then the casting shape/design or the “standard” metallurgical characteristics are not properly controlled, considered or modelled in the solidification simulation. In this paper we present the Phase I of a research project, which consists on a bibliographic review of the previous attempts to evaluate the relationship between solidification sequence and the measurement of expansion of molten metal during eutectic solidification and is relation to porosity and shrinkage defects.
19
Khan, Muhammad Azhar Ali. "Simulation Based Mold Design Optimization of a Spring Flap Casting." Solid State Phenomena 305 (June 2020): 178–84. http://dx.doi.org/10.4028/www.scientific.net/ssp.305.178.
Full textAbstract:
The complex nature of metal casting process brings about a need to simulate it before undertaken in a foundry. Casting simulations provide insights on flow of molten metal within the mold, solidification sequence, nature and location of defects etc. Moreover, mold design can be optimized to minimize defects without undergoing physical trials-and-errors as previously practiced in traditional metal casting. This study is based on casting an ASTM A216 WCB steel spring flap for automotive suspension system using a simulation based optimized mold design. The initial and optimized mold designs are simulated in MAGMASoft for mold filling, solidification, stress distribution and defects prediction. The results of simulations and actual castings are found to be in good agreement. It is concluded that simulations are accurate in modeling casting process and in predicting defects followed by their minimization through mold design optimization. The use of auxiliary components in a carefully designed mold can lead to a nearly defect-free and high quality cast product.
20
Kovtunov, A. I., D. A. Semistenov, Yu Yu Khokhlov, and S. V. Myamin. "The research of the processes of formation of porous non-ferrous metals." Vektor nauki Tol'yattinskogo gosudarstvennogo universiteta, no. 2 (2021): 9–17. http://dx.doi.org/10.18323/2073-5073-2021-2-9-17.
Full textAbstract:
Foamed metals are promising materials with a unique combination of mechanical and operational properties: low specific gravity, low thermal conductivity, ability to absorb acoustic and electromagnetic vibrations, and the ability to deform under a constant load. Currently, the most used methods for producing foamed aluminum and foamed magnesium are methods based on mixing gas or porophore into molten aluminum and forming a porous structure during the solidification of the aluminum melt. An alternative to this technology is the formation of a porous structure through the use of soluble granules that pre-fill the mold and after impregnating the granules with molten metal and solidifying the castings, they are leached. The work aims to determine the influence of casting modes and the size of granules on the depth of impregnation of granular filling with metal melt during the formation of porous aluminum castings. The authors proposed the technique for calculating the depth of impregnation of granular filling when producing castings of porous non-ferrous metals based on the calculation of melt cooling when moving along the thin-walled channel. The calculations made it possible to determine the depth of impregnation and establish the allowable wall thickness of the casting of porous aluminum, depending on the size of the granules used, the speed of the melt in a form, the mold temperature, and the temperature of molten aluminum. The study identified that to increase the depth of impregnation and obtain porous aluminum castings with thinner walls, it is advisable to increase the diameter of the salt granules and not the temperature and hydrodynamic modes of casting. The authors carried out calculations and identified the influence of the casting regimes and the diameter of the granules on the depth of mold impregnation to obtain porous castings from promising magnesium alloys.
21
Acimovic-Pavlovic, Zagorka, Milutin Djuricic, Sasa Drmanic, and Rade Djuricic. "The influence of the parameters of lost foam process on the quality of aluminum alloys castings." Chemical Industry 64, no. 2 (2010): 121–27. http://dx.doi.org/10.2298/hemind100301011a.
Full textAbstract:
This paper presents the research results of application of Lost foam process for aluminum alloys castings of a simple geometry. The process characteristic is that patterns and gating of moulds, made of polymers, stay in the mould till the liquid metal inflow. In contact with the liquid metal, pattern intensely and in relatively short time decomposes and evaporates, which is accompanied by casting crystallization. As a consequence of polymer pattern decomposition and evaporation a great quantity of liquid and gaseous products are produced, which is often the cause of different types of casting errors. This paper presents the results of a research with a special consideration given to detecting and analyzing the errors of castings. In most cases the cause of these errors are defects of polymer materials used for evaporable patterns production, as well as defects of materials for refractory coatings production for polymer patterns. The researches have shown that different types of coatings determine properties of the obtained castings. Also, the critical processing parameters (polymer pattern density, casting temperature, permeability of refractory coating and sand, construction of patterns and gating of moulds) significantly affect on castings quality. During the research a special consideration was given to control and optimization of these parameters with the goal of achieving applicable castings properties. The study of surface and internal error of castings was performed systematically in order to carry out preventive measures to avoid errors and minimize production costs. In order to achieve qualitative and profitable castings production by the method of Lost foam it is necessary to reach the balance in the system: evaporable polymer pattern - liquid metal - refractory coating - sandy cast in the phase of metal inflow, decomposition and evaporation of polymer pattern, formation and solidification of castings. By optimizing the processing parameters castings of required structural and mechanical characteristics could be achieved, casting defects characteristic for this process could be avoided with the result of the production costs saving. The presented results can be useful to define parameters of Lost foam process and its application in practice with objective to obtain castings with in advance specified quality.
22
Wang, Xin, and Zhi Jun Zhang. "Simulation of Flow Field and Temperature Tield in the Process of Filling and Solidification for K424 Alloy Thin-Walled Casting." Applied Mechanics and Materials 66-68 (July 2011): 1568–73. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.1568.
Full textAbstract:
In order to improve the utilization of K424 alloy, Z-Cast analysis software is used to get three-dimensional flow field and temperature coupling simulation in the process of K424 alloy castings filling, by considering the effection of pouring temperature, casting speed, shell thermal conductivity and temperature on the morphology of filling.A three-dimensional simulation of temperature changes in solidification process of molten metal was performed based on the filling simulation. The simulation results on flow field and temperature field shows the order of filling and solidification in different parts of the casting ,and determines the position where cold shut and misrun appears, which provides theoretical support to the improvement of technology plan.
23
Pysz, Stanisław, and Robert Żuczek. "The Analysis of Prototype Cast Constructions and the Assessment of their Technological and Exploitation Properties." Solid State Phenomena 237 (August 2015): 215–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.237.215.
Full textAbstract:
The article describes the application of various methods of rapid prototyping for manufacturing of prototype castings. This technology assumes that the properties of such a casting are similar to properties of a casting obtained in serial production involving die-casting technologies or high pressure die casting. However, other conditions of metal preparation, pouring, and the solidification process, related to the specificity of manufacturing of a single casting with the application of rapid prototyping, as compared to serial production generate different final properties. Numerical simulations of exploitation conditions, with the use of Ansys and Abaqus software, were conducted for selected constructions taking into account the final properties of a casting. MAGMASoft software was used for the analysis of the technological process for manufacturing of prototype castings, as well as in serial production. The article describes the consecutive stages for manufacturing of selected prototype castings - from the moment of designing to manufacturing of a ready-made element. The selected elements were produced with the use of rapid prototyping with a 3D Z-Corp printer and a FDM Titan machine, and then model sets were prepared for casting with the application of the lost wax casting technique.The conducted analysis was aimed at defining methodology for manufacturing prototype castings with the use of numerical simulation tools, especially the implementation of boundary conditions achieved as a result of solidification analysis and techniques of rapid prototyping. It was stated that final properties of a prototype casting and a serial casting may be different, which may impact the assessment of the construction under development. The use of numerical calculations for the assessment of a prototype and serial construction with exploitation parameters broadens the expertise with final properties of the analysed construction.
24
Hector, Louis G., Bulent Aksel, and Joseph Fridy. "Growth Instability During Nonuniform Directional Solidification of a Pure Metal Plate." Journal of Applied Mechanics 58, no. 2 (June 1, 1991): 326–33. http://dx.doi.org/10.1115/1.2897189.
Full textAbstract:
The singly periodic beam theory of freezing front growth instability in pure metal castings due to Richmond et al., (1990) is extended here to the more general case of a doubly periodic plate. The casting is cooled with a doubly periodic heat flux which oscillates along two orthogonal axes of the mold/casting interface. The cooling profile induces nonuniform growth of the freezing front and hence a strain distribution in the casting that leads to contraction of the metal at specific locations along the mold interface. Metal contraction is studied through calculation of the interface pressure. Growth instability occurs when the pressure falls to zero beneath a thickness minimum, thereby signalling the nucleation of an air gap, and simultaneously increases beneath a thickness maximum thereby enhancing the initial nonuniformity of the freezing front. The significant differences between the beam and plate theories for a given pure metal are found in the more extreme stress levels which accumulate within the plate, the magnitude of the admissible uniform cooling term and hence predicted times to air gap nucleation, and casting thickness at air gap nucleation as well as interface pressures beneath thickness maxima. The doubly periodic plate theory permits larger uniform cooling and hence earlier air gap nucleation beneath thickness minima than does the singly periodic beam theory with more severe interface pressures beneath thickness maxima.
25
Wang, Cheng Jun, Long Li, Chang Guo Xue, and Qiong Liu. "Research on the Influence of Multidimensional Vibration on Casting Filling Capacity Based on Discrete Element Method." Key Engineering Materials 693 (May 2016): 1263–71. http://dx.doi.org/10.4028/www.scientific.net/kem.693.1263.
Full textAbstract:
To analyze liquid metal flow in mold under multidimensional vibration condition, discrete element method (DEM) is taken to approximately stimulate liquid metal flow and to simulate numerically liquid metal flow filling process in casting technique under multidimensional vibration. The orthogonal experiment design is taken to study vibration dimension, frequency as well as amplitude influence on liquid metal filling capacity; Through EDEM platform, numerical simulation research in each test scheme can be carried out to get influence of filling time upon sensitivity degree of each parameter index so as to select the optimal test scheme. Casting experiment results in the self-made solidification test-bed under multidimensional vibration match the numerical simulation, showing that multidimensional vibration could significantly improve filling capacity of castings.
26
Gurusamy, P., S. Balasivanandha Prabu, and R. Paskaramoorthy. "The Effect of the Die Temperature on the Solidification Behaviour of the Al/SiCp Metal Matrix Composite: A Comparative Study of Experimental and Finite Element Analysis." Advanced Materials Research 893 (February 2014): 314–19. http://dx.doi.org/10.4028/www.scientific.net/amr.893.314.
Full textAbstract:
This paper discusses the influence of die temperature on the solidification behaviour of A356/SiCp composites fabricated by squeeze casting method. Information on the solidification studies of squeeze cast composites is somewhat scarce. Experiments were carried out by varying the die temperatures for cylindrical shaped composite castings K-type thermocouples were interfaced to the die and the temperature-time history was recorded to construct the cooling curves. The cooling curves are also predicted from the finite element analysis (FEA) software ANSYS 13. The experimental and predicted cooling curves are not in good agreement. In addition to, the experimental and theoretical solidification times are studied. It was understood that the increase in the die temperature decreases the cooling rate.
27
Zeng, Jian Min, and Yao He Zhou. "A New Sand Casting Process with Accelerated Solidification Rate." Materials Science Forum 686 (June 2011): 765–69. http://dx.doi.org/10.4028/www.scientific.net/msf.686.765.
Full textAbstract:
In order to solve the problems involved in coarse grains, macro and micro porosities initiated by low solidification rate in sand casting, an innovative counter-gravity sand casting process, Casing under Adjustable Pressure with Accelerated Solidification (CAPAS) was put forward in this paper. The hydrodynamics of mold filling for CAPAS is based on Bernoulli's principle. The mold and crucible were placed separately in the upper and lower chambers, with the feed tube connected between them. High-speed jet flow of air made negative pressure in the upper chamber. In this way, pressure differential was created between the two chambers. Thereby the molten metal in the crucible was forced to flow upward smoothly to fill the mold cavity. After mold filling, cold air was introduced into sand mold through aisles that are set within the mold, which results in strong convective heat exchange at the casting/mold interface. So solidification rate of casting increased dramatically. The microstructures of the aluminum castings were compared between CAP (Low pressure sand casting) and CAPAS by optical microscope. The results showed that the microstructure of CAPAS aluminum casting was much finer than that of CAP casting and tensile strength markedly increased.
28
Yulianto, Agus, Rudy Soenoko, Wahyono Suprapto, As’ad Sonief, Agung Setyo Darmawan, and Muhammad Debi Setiawan. "Microstructure and Hardness of Gray Cast Iron as a Product of Solidification in Permanent Mold." Materials Science Forum 991 (May 2020): 37–43. http://dx.doi.org/10.4028/www.scientific.net/msf.991.37.
Full textAbstract:
Molds of metal are widely used in the casting process. The cooling rate in solidification of castings product with metal molds on the outer side and inner side is different. Therefore, sizes and types of phase will be also different. This study aims to investigate the microstructure andhardness of gray cast iron. To realize this research, the gray cast iron melting process was carried out in an induction furnace. Melted gray cast iron was poured into a Ferro Casting Ductile mold that has been through a preheating process at a temperature of 300 o C. The gray cast iron is then tested for composition, microstructure and hardness. The test results show that the part containing morecementite phase will be harder.
29
Sun, Hsien-Chi, and Long-Sun Chao. "Analysis of Interfacial Heat Transfer Coefficient of Green Sand Mold Casting for Aluminum and Tin-Lead Alloys by Using a Lump Capacitance Method." Journal of Heat Transfer 129, no. 4 (December 31, 2006): 595–600. http://dx.doi.org/10.1115/1.2709975.
Full textAbstract:
During the casting process of green sand mold, air gaps will form between the metal and sand mold. The air gaps will make it difficult to analyze the heat transfer at the mold/metal interface. Generally, an interfacial heat transfer coefficient is employed to evaluate the heat flux transferred across the air gaps. Though the interfacial heat transfer coefficient is highly important, its value is not easily obtained by using the direct experimental or theoretical method. With temperature-measured data, some inverse methods can be used to predict the coefficient. However, the latent heat released and undercooling during the solidification of the molten metal and the moisture of the green sand mold complicate the associated temperature calculations. To overcome this difficulty, a lump capacitance method is proposed in this study to calculate the interfacial heat transfer coefficient for the casting process in green sand mold. Thermalcouples are utilized to measure the temperatures of sand mold and metal. The geometry of casting is cylindrical and the castings are A356 alloy and Sn-20 wt. % Pb alloy. With the predicted interfacial coefficients, the temperature field of the metal was solved numerically. Based on the solidification time, the numerical results are in good agreement with the experimental ones. This verified the feasibility of the proposed method and it can be applied in the future study or design of a casting process.
30
Arab, N. "Competitive Nucleation in Grey Cast Irons." Archives of Foundry Engineering 17, no. 4 (December 20, 2017): 185–89. http://dx.doi.org/10.1515/afe-2017-0155.
Full textAbstract:
AbstractCast irons are good examples of materials which are more sensitive to chemical composition and production conditions. In this research to improve casting quality, solidification and nucleation process in grey cast iron was investigate. In particular, attempts have been made to rationalize variation in eutectic cells with nucleation sites and eutectic solidification undercooling. Four castings with different diameter and similar chemical composition and pouring temperature and different inoculant percentage was casted. The cooling curve and maximum and minimum undercooling for each castings was measured. Also optical metallography and image analyzer has been used to determine the average eutectic cells diameter, and linear and surface densities, and volume density was calculated. The results of this research show a competitive behavior between nucleation sites and eutectic undercooling. Higher nucleation sites and higher eutectic undercooling cause higher eutectic cell density. But increasing nucleation sites by introducing inoculants to molten metal, is accompanied with reduction in eutectic undercooling. It means that inoculation and undercooling have opposite effect on each other. So, to achieve maximum cell density, it is necessary to create an optimization between these parameters.
31
Djurdjevič, M., and M. Grzinčič. "The Effect of Major Alloying Elements on the Size of Secondary Dendrite Arm Spacing in the As-Cast Al-Si-Cu Alloys." Archives of Foundry Engineering 12, no. 1 (January 1, 2012): 19–24. http://dx.doi.org/10.2478/v10266-012-0004-2.
Full textAbstract:
The Effect of Major Alloying Elements on the Size of Secondary Dendrite Arm Spacing in the As-Cast Al-Si-Cu Alloys A comprehensive understanding of melt quality is of paramount importance for the control and prediction of actual casting characteristics. Among many phenomenon that occur during the solidification of castings, there are four that control structure and consequently mechanical properties: chemical composition, liquid metal treatment, cooling rate and temperature gradient. The cooling rate and alloy composition are most important among them. This paper investigates the effect of the major alloying elements (silicon and copper) of Al-Si-Cu alloys on the size of secondary dendrite arm spacing. It has been shown that both alloying elements have reasonable influence on the refinement of this solidification parameter.
32
Molnár, Dániel, and Jenő Dúl. "The Influence of the Solidification Process to the Dimensional Accuracy of Castings." Materials Science Forum 649 (May 2010): 431–36. http://dx.doi.org/10.4028/www.scientific.net/msf.649.431.
Full textAbstract:
The real system under consideration comprises of a solidifying casting with the casting mould, environment and other external influences. The process observed begins with the introduction of liquid metal to the channels of the runner system and filling of the mould cavity. This is connected with the contact of liquid metal with the atmosphere and also, with the walls of the mould. During the filling of the mould cavity heat transfer between the metal surface and the walls of the mould takes place (by radiation and conduction), which in practice can lead to mould cracking, and next to the formation of casting surface defects. In this stage of the process of great significance are the hydrodynamic conditions. These are dependent on the metal itself (its viscosity), and also on the runner system (rate of flow, resistances). During this time in the volume of the casting and mould, a pseudo-initial temperature fields is generated which is significant for the filling of the mould cavity and also for further cooling and solidification of the casting.
33
Žbontar, Matic, Mitja Petrič, and Primož Mrvar. "The Influence of Cooling Rate on Microstructure and Mechanical Properties of AlSi9Cu3." Metals 11, no. 2 (January 21, 2021): 186. http://dx.doi.org/10.3390/met11020186.
Full textAbstract:
The aim of this study was to determine the correlation between the size and the distribution of microstructural constituents and their cooling rate, as well as the correlation between the mechanical properties and the cooling rate of AlSi9Cu3 aluminum alloy when cast in high-pressure die casting (HPDC) conditions. In other words, the ultimate goal of the research was to determine the mechanical properties for a casting at different cooling rates. Castings with different wall thicknesses were chosen, and different cooling rates were assumed for each one. Castings from industrial technological practice were systematically chosen, and probes were extracted from those castings for the characterization of their mechanical properties. Special non-standard cylinders were created on which compressive tests were carried out. The uniqueness of this research lies in the fact that the diameters of the designed cylinders were in direct correlation to the actual wall thickness of the castings. This is important because the solidification of metal in the die cavity is complex, in that the cooling rates are higher on the surface of the casting than in the center. Local in-casting cooling rates were determined using numerical simulations. It was discovered that with increasing cooling rates from 60 K/s to 125 K/s the values for strength at 5% deformation increased on average from 261 MPa to 335 MPa.
34
Majerník, Ján, Monika Karková, and Ján Kmec. "Assessment of Suitability of the Design of Gating System with the Use of Simulation Software." Key Engineering Materials 756 (September 2017): 136–41. http://dx.doi.org/10.4028/www.scientific.net/kem.756.136.
Full textAbstract:
The quality of thin wall castings produced by metal die-casting depends on the coherence and consistency of various aspects influencing the process of casting cycle. The qualitative properties of castings should already be considered in the design phase of construction of the gating system. The simulation software is an effective facility for the initial revealing of defects of the design phase. The assessment of casting cycle by the means of simulation predicts an incidence of defects of the casting core in the design phase and therefore reduces both the incidence of defects in the production and the costs while the production efficiency is increased. The article deals with the assessment of the design of the gating system for a particular casting type. The filling of mould cavity, casting solidification and time course of temperature changes occurring in the selected locations of gating system were defined as parameters indicating the assumptions of design accuracy. Simulation tests were carried out in the NovaFlow&Solid program. The tests resulted in a conclusion evaluating and describing the adequacy of structural design of the gating system.
35
Selvaraj, J., M. Thenarasu, S. Aravind, and P. Ashok. "Waste Heat Recovery from Castings and Scrap Preheating by Recovered Heat Using an Intermediate Heat Transfer Medium." Applied Mechanics and Materials 813-814 (November 2015): 776–81. http://dx.doi.org/10.4028/www.scientific.net/amm.813-814.776.
Full textAbstract:
Energy conservation is a major topic of concern since our energy sources are exhausting exponentially. This paper focuses on waste heat recovery using which scrap preheating is done in metal castings using sand molds. During solidification of molten metal, most of the heat is lost to the sand. The proposal is to prepare the sand mould with aluminium shots surrounding the mold cavity. These shots absorb some of the heat from the solidifying metal in the mold cavity. The heated shots are separated from the mold and they are allowed to transfer their heat energy to the metal scrap by conduction. The experiments indicate that at least 6.4% of heat recovery is achievable. This will be instrumental in reducing the enormous amount of energy spent to melt the metal considering the fact that casting is the most widely used manufacturing process globally.
36
Ardeleanu, Laurenţiu, Constantin Bratu, and Ioan Mărginean. "Effects of Vibration and Salts Treatments on Aluminium Alloy Properties Used in Mould Manufacture." Advanced Materials Research 1128 (October 2015): 58–63. http://dx.doi.org/10.4028/www.scientific.net/amr.1128.58.
Full textAbstract:
Metallic mould properties are influenced by the technological process used on casting. The mechanical properties of aluminium castings can be affected by dissolved gases, heterogeneous impurities or shrinkage remaining in casting after solidification. Dissolved gases and oxide inclusions in aluminium all have a deleterious effect on casting quality. The treatment of molten aluminium using vibrations and salts was found to be highly efficient in refining the microstructure of the alloy. The main objective of the paper is to understand the effects of vibrations and salts treatment on the final microstructure and changes that take place and influences aluminium alloy properties used in mould manufacture. The microstructural changes have a great significance in improving the properties of aluminium alloy castings. Understanding this effects and the modification mechanism can undoubtedly be of great significance for improving casting quality. Fluxes based on a KCl-NaCl mixture may be used to cover and protect the metal from oxidation. Most fluxes are based on a mixture of KCl and NaCl, which forms at low-temperature (665 °C) eutectic.
37
Kordas, P. "Influence of the conditions of casting and heat treatment on the structure and mechanical properties of the AlMg10 alloy." Journal of Achievements in Materials and Manufacturing Engineering 1, no. 83 (July 1, 2017): 26–32. http://dx.doi.org/10.5604/01.3001.0010.5137.
Full textAbstract:
Purpose: Assessment of the possibilities of shaping the structure and improvement of mechanical properties of casting from AlMg10 alloy through a selection of casting technology and precipitation hardening. Design/methodology/approach: the work evaluated the impact of casting and heat treatment technology on the mechanical properties and structure of AlMg10 alloy castings. The tests were performed on 200 mm × 100 mm × 25 mm plate castings produced by gravity casting methods for sand and metal moulds and by a liquid state press moulding technology. Castings made with these technologies solidify in substantially different heat- evaporation conditions and exhibit varying degrees of primary structure fragmentation. Metallographic and strength tests were performed on raw castings and after heat treatment. Findings: The changes in the morphology and size of primary crystals and the dispersion of the reinforcing phase according to the casting solidification rate and the precipitation hardening treatment were analyzed. Solidifying castings in the form of sand show a globular structure, whereas in die and press castings, a typically dendritic structure occurs, with the dendritic crystals in pressed castings being much smaller in size than the die castings. In castings which were not heat-treated, the reinforcing phase of Al3Mg2 occurs in interdendritic spaces, and its dispersion increases with the rate of cooling. After supersaturation and ageing treatments, the phase α has a grain structure in all samples. The largest dispersion of reinforcing molecules is characterized by press castings. In a raw state, the highest mechanical properties are shown by castings made in the form of sand and the method of pressing in a liquid state. Heat treatment of AlMg10 alloy castings significantly influences the increase of mechanical indexes in all castings investigated. The highest features of Rm are approx. 330 MPa and A5 above 10% is obtained in castings made by the press method. Research limitations/implications: Particular attention should be paid to the avoidance of the effects of slag inclusion, shrinkage and magnesium oxidation during casting of AlMg10 alloys. In die castings of a plate type, due to own stresses, a significant decrease in mechanical properties occurs. Practical implications: The most advantageous mechanical properties of AlMg10 alloy castings are obtained by using liquid-state pressing technology. In addition, this technology makes it possible to produce thin-walled castings of high dimensional accuracy, high air- tightness, fine grain structure, lack of surface defects and low roughness. Originality/value: The paper presents the possibility of improving the mechanical properties of AlMg10 castings by applying heat treatment. It has been proven that the casting method has a significant effect on the mechanical properties of the castings.
38
Marukovich, E. I., and V. Yu Stetsenko. "Effect of gases released during solidification of castings on microstructure of alloys." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 2 (June 9, 2020): 12–14. http://dx.doi.org/10.21122/1683-6065-2020-2-12-14.
Full textAbstract:
Thermodynamic calculation of formation of spherical gas bubbles different in water – wetting on flat surfaces by metal melt is made. This process consists of two stages. The first stage is formation of equilibrium gas bubble in the form of ball segment. The second stage is its swinging into a spherical bubble. Calculations were made for gas bubbles with constant volume. It is shown that Gibbs energy of spherical gas bubble formation on water – wetting metal melt substrate is three times less than on nonwettable melt substrate. Thus, gases released by solidification of the castings will preferably be formed and removed as bubbles on the molten metal surfaces of the crystallizable phases of the alloys and directly affect on their microstructure.
39
Hussainy, Syed Ferhathullah, Mohd Viquar Mohiuddin, P. Laxminarayana, S. Sundarrajan, and A. Krishnaiah. "Analysis of Shrinkage Characteristics of Aluminium Silicon Alloy." Journal for Manufacturing Science and Production 16, no. 3 (September 1, 2016): 163–71. http://dx.doi.org/10.1515/jmsp-2016-0002.
Full textAbstract:
AbstractAnalysis of shrinkage characteristics of Aluminium-Silicon alloy was studied theoretically and experimentally. The Aluminium alloys considered in the study are A413 (LM6), A360 (LM9) and A380 (LM24). Extensive literature survey has suggested that cavity filling and solidification process are two most critical aspects to produce high quality casting components. A statistical model of parameters and response to understand the influence of parameters on shrinkage and casting yield studies has been presented. Experiments were conducted in foundry in industrial environment to produce commercially treated aluminium alloy castings in sand mould. Alloy was found to be most significant factor influencing shrinkage. The yield of casting was improved using insulating and exothermic sleeves. Solidification time of exothermic riser was 10 % more than insulated riser. Thus, in order to produce radiographic quality casting a theoretical and experimental method is presented so that number of trials in foundry is reduced which leads to increased reliability and productivity. Study also shows that by using sleeves considerable metal is saved, energy saving during melting, improved quality, reduced cost and increased capacity of plant can be achieved.
40
Huang, Pei-Hsing, Jenn-Kun Kuo, Te-Hua Fang, and Wei-ren Wu. "Numerical simulation and design of casting system for stainless steel exhaust manifold." MATEC Web of Conferences 185 (2018): 00008. http://dx.doi.org/10.1051/matecconf/201818500008.
Full textAbstract:
During operation, exhaust manifolds must bear the corrosion of high temperatures and repeated stress, which can easily lead to cavitation, corrosion, and creeping damage in the casting structure and affect product safety. To improve the structure of exhaust manifolds and increase their service life, we employed AnyCasting mold flow analysis to SUS304 stainless steel exhaust manifolds. We examined the influence of casting system design and process parameters such as ceramic shell temperature, casting temperature, and pouring speed on the filling and solidification processes of the liquid metal. Finally, we used the Niyama criterion to predict the probability and distribution of shrinkage porosity defects in the exhaust manifold and made improvements to enhance the quality of exhaust manifold castings. Keywords: exhaust manifold, mold flow analysis, casting system.
41
Leranth, Gabor. "Solidification Time Estimation and Simulation - In Case of HPDC." Materials Science Forum 649 (May 2010): 467–72. http://dx.doi.org/10.4028/www.scientific.net/msf.649.467.
Full textAbstract:
Since cast parts are used by the mankind -and the casting method should be one of the oldest metal forming technologies- the foundrymen struggle with various kind of difficulties. The most elementary ones are thermal problems during pouring. The basic condition, filling the mould before the metal solidifies to get the whole required shape, underlies primarily the thinnest wall within the casting and the thermal conditions. The empiric, experience-based knowledge was for a long time the single clue at the practical work with castings. Chvorinov, in German-speaking publications also written as Chworinoff, summarized and through his theoretical as well as experimental work complemented the knowledge of his time concerning the estimation of solidification development in sand-casted steel parts. His theory –expressed with the certainly best known formula in this speciality- was later expanded, modified and adapted to new scientific informations, although in a different way regarding the German-speaking respectively Anglo-Saxon technical literature. Nowadays, in time of more correct predictions supported through modern tools, estimation formulas are still very useful, acting as a preliminary stage of the design and development. Numerical simulation, in effect the efficient instrument for the subsequent steps of the processing, can also help to make the basic approximations more accurate, but it has his own possible traps as well.
42
Bertelli, Felipe, Elisangela dos Santos Meza, Debora de Jesus Bezerra, Pedro R. Goulart, Noé Cheung, and Amauri Garcia. "Heat Transfer Characteristics of Inward, Outward and Upward Solidification of an Al-1.5wt%Fe Alloy in Cylindrical Chill Molds." Materials Science Forum 730-732 (November 2012): 805–10. http://dx.doi.org/10.4028/www.scientific.net/msf.730-732.805.
Full textAbstract:
In this work, three water-cooled experimental solidification devices were developed, and experiments were carried out with an Al-1.5wt%Fe alloy. The three experimental setups consist of vertical cylindrical steel molds with each of them having different zones cooled by water. For the inward solidification, a cooled tube is used having its upper and bottom part thermally insulated. For the outward solidification, a cooled tube, forming an inner part, is concentrically placed inside a cylindrical mold, which is thermally insulated from the environment, by using insulating materials. For the upward solidification, the bottom part of the mold is water-cooled and consists of a thin (3 mm) disc of carbon steel, whilst the cylindrical surface is covered with insulating material to avoid lateral heat losses. A numerical solidification model based on the finite difference method is applied for the simulation of the three aforementioned cases of solidification from the chilled surface considering transient heat flow conditions. Experimental thermal readings in the castings have been used for the determination of the transient overall metal/coolant heat transfer coefficient, h, through a numerical-experimental fit of casting thermal profiles based on inverse heat transfer calculations. It was found a significant variation of h as a function of time during solidification in the three cylindrical set-ups experimentally examined, including a remarkable increase in h during the outward solidification. Introduction
43
Mohapatra, Shubhashree, Hrushikesh Sarangi, and Upendra Kumar Mohanty. "Effect of processing factors on the characteristics of centrifugal casting." Manufacturing Review 7 (2020): 26. http://dx.doi.org/10.1051/mfreview/2020024.
Full textAbstract:
Centrifugal castings are produced by pouring liquid metal into rotating moulds. It solidifies under the influence of centrifugal forces, directed from the center to the periphery of the mould on account of mould rotation, and exhibits directionality in solidification which helps to eliminate voids and discontinuities in the resultant casting, usually encountered in gravity castings. Also, a compositional gradient is sat up in the melt which can be monitored, to produce functionally graded materials (FGMs) of choice with multi-functionality. The pouring rate, pouring temperature, mould temperature, and mould material can be suitably selected and altered in isolation or in combination, to generate a desired thermal gradient in the melt which decides its cooling rate. The cooling rate of the melt has the greatest impact on the grain structure of the casting. On the other hand, the grain structure of the casting governs its mechanical performance and decides the suitability for any specific end-use. Thus, different processing factors influence the characteristics of centrifugal casting. In the present article, a sincere attempt is made to analyze the effect of these factors and to enumerate the role played by each one of these factors in deciding the centrifugal casting characteristics.
44
Bichler, Lukas, and Comondore Ravindran. "Formation of Fold Defects in Permanent Mold Cast AE42 Magnesium Alloy." Materials Science Forum 638-642 (January 2010): 1591–95. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.1591.
Full textAbstract:
Application of magnesium alloys potentially plays a key role in weight reduction of automotive and aerospace components. Majority of magnesium components are manufactured via the high-pressure die-casting (HPDC) or permanent-mold casting (PMC) processes. In general, castability of magnesium alloys is comparable to aluminum alloys. However, unique defects related to the high susceptibility of magnesium to rapidly solidify, dissolve hydrogen or form oxides potentially contribute to material failure. In this research, AE42 magnesium alloy castings were manufactured via the PMC process. Formation of fold defects in regions of high melt turbulence was observed on the macro-scale as visible surface flow-lines. Microstructural analysis revealed that folds in the AE42 alloy we related to the rapid solidification and short alloy freezing range. Further, segregation of Al2RE intermetallics at the metal front hindered proper fusion of merging metal fronts.
45
Chelliah, Nagaraj M., Padaikathan Pambannan, and MK Surappa. "Effects of processing conditions on solidification characteristics and mechanical properties of in situ magnesium metal matrix composites derived from polysilazane precursor." Journal of Composite Materials 53, no. 26-27 (May 2, 2019): 3741–55. http://dx.doi.org/10.1177/0021998319846546.
Full textAbstract:
Polymer-derived in situ magnesium metal matrix composites (P-MMMCs) were fabricated by injecting a liquid or cross-linked polysilazane precursor into molten magnesium by a stir-casting method at two different melt temperatures of 700 and 800℃. Microstructural analysis reveals that the composites fabricated at 700℃ exhibit uni-modal grain size distribution having more or less columnar-shaped grain morphology. On the contrary, bi-modal grain size distribution with predominantly dendritic grain morphology occurs in the Mg matrix composites fabricated at 800℃. Such difference in grain morphology can be associated with variation in the availability of heterogeneous nucleation sites, and direction of heat flux during solidification. All of the fabricated composites were investigated for their solidification characteristics, microstructural evolution, micro/nano-hardness and compression properties. This article discusses the correlation between the processing parameters, microstructural evolution and mechanical properties of the as-cast in situ composites fabricated by liquid metallurgical route. Polymer-injection followed by in situ pyrolysis holds the potential of revolutionary processing technologies for producing castings of metal matrix nanocomposites, for example by bubbling the organic liquid with a carrier gas, e.g. nitrogen, into the molten metal by a Bessemer-like process.
46
Gede Sugita, I. Ketut, R. Soekrisno, I. Made Miasa, and Suyitno Suyitno. "The effect of solidification rate on morphology microstructures and mechanical properties of 80%Cu-20%Sn bronze alloys." Material Science Research India 7, no. 1 (June 25, 2010): 59–66. http://dx.doi.org/10.13005/msri/070106.
Full textAbstract:
The purpose of this study is to investigate the morphology of solidification microstructures 80% Cu-20%Sn on different solidification rate. The commercial pure copper and tin were melted in crucible furnace at temperature 1000oC. The molten metal was casted in permanent moulds which have variation temperature, i.e. 35oC, 200oC, 400oC. The cooling curves of the castings were recorded using a computer aided data acquisition system. The microstructure and mechanical properties of this alloy have been investigated. The results of this research indicate that decreasing the mould temperatures affected on increasing solidification rate that caused to reduce the solidification time. The difference of solidification rate have effected on microstructure morphology. The secondary dendrite arm spacing (SDAS) decreases with increasing solidification rate, the hardness and strength increase correspondingly. The distribution of hardness cast product increased from the center to outside the cast specimens.
47
Amin, M. Ruhul, and Nikhil L. Gawas. "Conjugate Heat Transfer and Effects of Interfacial Heat Flux During the Solidification Process of Continuous Castings." Journal of Heat Transfer 125, no. 2 (March 21, 2003): 339–48. http://dx.doi.org/10.1115/1.1560146.
Full textAbstract:
Multiphase fluid flow involving solidification is common in many industrial processes such as extrusion, continuous casting, drawing, etc. The present study concentrates on the study of air gap formation due to metal shrinkage on the interfacial heat transfer of a continuous casting mold. Enthalpy method was employed to model the solidification of continuously moving metal. The effect of basic process parameters mainly superheat, withdrawal velocity, mold cooling rate and the post mold cooling rate on the heat transfer was studied. The results of cases run with air gap formation were also compared with those without air gap formation to understand the phenomenon comprehensively. The current study shows that there exists a limiting value of Pe above which the effect of air gap formation on the overall heat transfer is negligible.
48
Anca, Denisa, Iuliana Stan, Mihai Chisamera, Iulian Riposan, and Stelian Stan. "Experimental Study Regarding the Possibility of Blocking the Diffusion of Sulfur at Casting-Mold Interface in Ductile Iron Castings." Coatings 11, no. 6 (June 1, 2021): 673. http://dx.doi.org/10.3390/coatings11060673.
Full textAbstract:
The main objective of this work is to investigate the mechanism of sulfur diffusion from the mold (sand resin P-toluol sulfonic acid mold, sulfur-containing acid) in liquid cast iron in order to limit the graphite degeneration in the surface layer of iron castings. A pyramid trunk with square section samples was cast. On the opposite side of the feed canal of the samples, steel sheets with different thicknesses (0.5, 1, and 3 mm) were inserted with the intention of blocking the diffusion of sulfur from the mold into the cast sample during solidification. The structure evaluation (graphite and matrix) in the surface layer and the casting body was recorded. The experimental results revealed that by blocking the direct diffusion of sulfur at the mold-casting interface, a decrease of the demodified layer thickness (for 0.5 mm steel sheet thickness) is obtained until its disappearance (for steel sheet thicknesses of more than 1 mm). The paper contains data that may be useful in elucidating the mechanism of graphite degeneration in the superficial layer of ductile iron castings. Based on the obtained results, we recommend using such barriers on the metal-mold interface, which are able to limit sulfur diffusion from the mold/core materials into the iron castings, in order to limit or even cease graphite degeneration in the Mg-treated surface iron casting layer. The paper presents additional data related to the interaction of sulfur at the ductile iron casting-mold interface previously analyzed.
49
Liao, Dun Ming, Li Liang Chen, Jian Xin Zhou, and Rui Xiang Liu. "CAD/CAE Technology and its Application on Nonferrous Alloy Casting." Advanced Materials Research 139-141 (October 2010): 1113–16. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.1113.
Full textAbstract:
The nonferrous alloy castings will be much demanded with the development of aerospace, light-weight weapons and automotive industry. Casting CAD/CAE technology has played an increasingly important role in foundry. It can help technician to design casting process and simulate heat transferring and molten metal flowing before actual production. Firstly, the main contents and basic principles, mathematical models of casting CAD and CAE were introduced. Secondly, the casting CAD/CAE technology route was interpreted, and then several CAD/CAE applications of casting process design and simulating were carried out on nonferrous alloys, such as aluminum, magnesium and copper. The results indicate that CAD/CAE technology can be applied to casting process design and predict casting defects which usually occur during the casting mold filling and solidification process, it can provide references to optimize casting process, so as to improve casting quality, reduce the rejection rate and shorten the development cycle of new products.
50
Sierant, Z. "Optimisation of the Deoxidation Degree and Modification on the Cast Steel Properties Improvement at Low Temperature." Archives of Metallurgy and Materials 58, no. 3 (September 1, 2013): 763–67. http://dx.doi.org/10.2478/amm-2013-0068.
Full textAbstract:
Abstract Industrial conditions of obtaining thick-walled and shaped castings intended for operations at temperatures: minus 40÷60°C are presented in the paper. The selection of a cast steel grade is based on known studies [1,10,14], however due to castings wall thickness (70-240mm), the way of preparing liquid metal (deep deoxidation and modification, argon stirring in a ladle) and conditions of filling mould cavities (gating system assuring quiet filling, directional solidification and avoiding a formation of inessential heat centres), were developed to assure the required impact strength. Maintaining these parameters as well as the selection of heat treatments for the produced massive castings allowed to achieve the impact strength over 50 J/cm2 at minus 40°. This value was obtained for walls of various thickness