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As materials science continues to advance, the correlation between microstructure and macroscopic properties has garnered growing interest for optimizing and predicting material performance under various operating conditions. The phase-field method has emerged as a crucial tool for investigating the interplay between microstructural characteristics and internal material properties. In this study, we propose a phase-field approach to couple two-phase growth with stress–strain elastic energy at the mesoscale, enabling the simulation of local stress effects on the solidified structure during the plasma cladding of WC particles and nickel-based alloys. This model offers a more precise prediction of microstructural evolution influenced by stress. Initially, the phase field of WC-Ni binary alloys was modeled, followed by simulations of actual local stress conditions and their impacts on WC particles and nickel-based alloys with ProCAST and finite element analysis software. The results indicate that increased stress reduces grain boundary migration, decelerates WC particle dissolution and diffusion, and diminishes the formation of reaction layers and Ostwald ripening. Furthermore, experimental validation corroborated that the model's predictions were consistent with the observed microstructural evolution of WC particles and nickel-based alloy composites. [ABSTRACT FROM AUTHOR]

The vertical centrifugal casting of 2219Al/AZ31B alloy bimetallic ring blank is performed using ProCAST software. The influence of rotation speed of casting mold and the pouring interval between the inner layer and outer layer on the interface bonding behavior were studied. The results show that the filling process of the metal liquid is more stable with the increasing rotation speed. A fewer shrinkage defects near to the bonding interface of the bimetallic ring blank are obtained at the rotation speed of 500-600 r min−1. The heat dissipation speed at the outer layer is accelerated with the increasing pouring interval, which results in the metallurgical bonding is more difficult for the inner and outer layers. The pouring interval of 386 s and rotation speed of 500 r min−1 are recommended to the optimum casting parameters, contributing to a sound bonding interface. At these conditions, the axial metallurgical bonding height of approximately 190.34 mm is achieved. The microstructure at the bonding interface is composed of coarse equiaxed grains near to the inner surface of the outer layer and fine equiaxed grains near to the outer surface of the inner layer. [ABSTRACT FROM AUTHOR]

Many practical high-pressure die casting process (HPDCP) optimization problems are multi-objective optimization ones that optimize multiple quality attributes of castings, simultaneously. This paper proposed a new HPDCP optimization method for improving volume of shrinkage porosity (VSP) and air entrainment (AE) using Taguchi-based ProCAST simulation and multi-attribute decision-making (MADM)-based overall quality index. Taguchi orthogonal array was used to design ProCAST simulation experiment. MADM was used to convert multiple quality attributes into a single overall quality index (OQI). Taguchi optimization method was used to determine the optimal HPDCP parameters to maximize the OQI. By using the proposed method, this paper determined the optimal HPDCP parameters such as pouring temperature (PT), filling rate in shot sleeve (FR), piston velocity (PV) and preheating mold temperature (PMT) for improving the VSP and AE in carburetor housing with aluminum alloy AlSi9Cu1Mg. The optimal HPDCP parameters were PT of 640 °C, FR of 40%, PV of 6.5 m/s, and PMT of 150 °C. The PT was the most effective HPDCP parameter for improving the VSP and AE, and the next were FR, PV, and PMT. The proposed method could be actively applied to not only HPDCP but also other casting processes and other manufacturing processes. [ABSTRACT FROM AUTHOR]

Copyright of Metal Working (1674-165X) is the property of Metal Working Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Foundry Technology (1000-8365) is the property of Foundry Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of mold rotation speed, pouring temperature, preheating mold temperature, pouring rate and coating thickness on the solidification time, shrinkage porosity and melt velocity in vertical centrifugal casting were investigated. To minimize computation time and obtain adequate estimate of the effects, a Fractional Two – Level Factorial Design 2(5–1) was applied. The results were obtained by numerical simulations using ProCAST software. The regression model was developed using Design Expert software. The analysis of variance revealed that the coating thickness had the most pronounced effect on the solidification time and shrinkage porosity. Finally, the procedure for selecting the optimal factors was carried out by application of multi objective optimization. The shortest solidification time was 20.68 s, while the shrinkage porosity was negligible, and it was achieved with the highest value of mold rotation speed and the lowest values of pouring temperature, preheating mold temperature, pouring rate and coating thickness. [ABSTRACT FROM AUTHOR]

In this study, the filling and solidification processes of squeeze-casting SiC3D/Al composites were analyzed by the ProCAST simulation software (ver. 2018.0). A practical squeeze-casting experiment was conducted to verify the accuracy of the simulation results. A series of orthogonal experiments were conducted on the initial preheating temperature of various components to identify the optimal parameters in order to achieve better porosity and stress concentration values. According to the results and analyses, the preheating temperature of the mold was the most important determining factor. Under a pouring temperature of 700 °C, mold preheating temperature of 200 °C, and SiC skeleton preheating temperature of 600 °C, the maximum principal stress at the bottom of the products was decreased by about 41.9%, and the shrinkage volume inside the composite was decreased about by about 61.6%. Thus, by adjusting the initial preheating temperature of various components, the squeeze-casting SiC3D/Al composites could achieve better performance and fewer internal defects. [ABSTRACT FROM AUTHOR]

As materials science continues to advance, the correlation between microstructure and macroscopic properties has garnered growing interest for optimizing and predicting material performance under various operating conditions. The phase-field method has emerged as a crucial tool for investigating the interplay between microstructural characteristics and internal material properties. In this study, we propose a phase-field approach to couple two-phase growth with stress–strain elastic energy at the mesoscale, enabling the simulation of local stress effects on the solidified structure during the plasma cladding of WC particles and nickel-based alloys. This model offers a more precise prediction of microstructural evolution influenced by stress. Initially, the phase field of WC-Ni binary alloys was modeled, followed by simulations of actual local stress conditions and their impacts on WC particles and nickel-based alloys with ProCAST and finite element analysis software. The results indicate that increased stress reduces grain boundary migration, decelerates WC particle dissolution and diffusion, and diminishes the formation of reaction layers and Ostwald ripening. Furthermore, experimental validation corroborated that the model’s predictions were consistent with the observed microstructural evolution of WC particles and nickel-based alloy composites.

Impellers must have no defects to endure vibration and centrifugal force. The shell for producing the impeller is located at tilt and the runner/riser system is optimized to obtain good quality casting and increase the casting yield. Sprue is adopted as riser to increase casting yield and ProCAST is employed to analyze solidification behavior of molten metal according to dimensions of the riser and gate. Although the diameter of riser was decreased from 133 to 66 mm through the simulation, no shrinkage defect was occurred in the castings due to the proper size and location of the runner/riser system. The occurring of the gas and non-metal inclusion defects was evaluated in castings by tilting the shell at 0°, 5°, 10°, 15° and 20°. The ultrasonic detecting results show that the proper design of the runner/riser systems and mold tiling eliminated the casting defects such as shrinkage, gas and non-metal inclusion. In addition, the casting yield was increased from 41.5 to 65.2%. [ABSTRACT FROM AUTHOR]

The study focused on addressing casting defects in green sand casting that have negatively impacted the quality of the butterfly valve body. By employing various methods such as observation, interviews, numerical experimentation, and simulation, the researchers aimed to develop and evaluate a sand-casting technique for the butterfly valve body. Solidworks software was used to model the component and its gating system, while ProCAST software enabled mold filling and solidification analyses. The goal was to minimize shrinkage porosities in the cast butterfly valve body by optimizing process parameters through numerical experiments and the Taguchi technique. Analysis of variance (ANOVA) using Minitab 18 software analyzed the results. Through this research, the sand mold-related defect was reduced from 10% to 3%, and the special shrinkage defect was reduced from 26% to 2% by using a simulation of casting. [ABSTRACT FROM AUTHOR]

Understanding the infiltration and solidification processes of liquid 5083Al alloy into Al2O3 three-dimensional reticulated porous ceramic (Al2O3(3D) RPC) is essential for optimizing the microstructure and properties of Al2O3(3D)/5083Al interpenetrating phase composites (IPCs) prepared by low-pressure infiltration process (LPIP). This study employs ProCAST software to simulate the infiltration and solidification processes of liquid 5083Al with pouring velocities (PV) of 0.4 m/s infiltrating into Al2O3(3D) RPC preforms with varying porosities at different pouring temperatures (PT) to prepare Al2O3(3D)/5083Al IPCs using LPIP. The results demonstrate that pore diameter of Al2O3(3D) RPC preforms and PT of liquid 5083Al significantly influence the of the infiltration. Solidification process analysis reveals that the Al2O3(3D) RPC preform with smaller pore diameters allows the lower pouring velocity of 5083Al to solidify faster compared to the preform with larger pore diameters. Al2O3(3D)/5083Al IPCs were prepared successfully from Al2O3(3D) RPC porosity of 15 PPI with liquid 5083Al at PV 0.4 m/s and PT 800 °C using LPIP, resulting in nearly fully dense composites, where both Al2O3(3D) RPCs and 5083Al interpenetrate throughout the microstructure. The infiltration and solidification defects were reduced under air pressure of 0.3 MPa (corresponding to PV of 0.4 m/s) during LPIP. Finite volume method simulations are in good agreement with experimental data, validating the suitability of the simplified model for Al2O3(3D) RPCs in the infiltration simulation. [ABSTRACT FROM AUTHOR]

Dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) is an energetic ionic salt that has many advantages over conventional explosives, including high detonation speed, high energy, and low toxicity. Although the properties of TKX-50 have been explored in many aspects, TKX-50/2,4,6-trinitrotoluene (TNT) based melt cast explosives are not yet reported. Herein, this work investigated the application of TKX-50 in melt cast explosives by using TNT as the dispersant and TKX-50 as the high-energy component. The effect of micro-and nano-sized TKX-50 particles on the properties of the castable explosives was investigated. The TKX-50-based castable explosives were characterized through scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry, velocity of detonation measurement, and vacuum stability testing. Moreover, ProCAST, a finite element casting simulation software, was used to study the temperature field changes and predict the locations of defects generated during the solidification process of melt cast explosives, and the simulated results are consistent with the experimental results. Hence, this work provided a new prospect of micro-and nano-sized TKX-50 particles in castable explosives. [ABSTRACT FROM AUTHOR]

The inseparability of material macroscopic properties and microstructure has prompted scholars to continuously delve into microstructural studies. The phase-field method has become an important basis for modern microstructure simulation techniques. The difficulty of the phase-field method lies in the modeling and parameter input. In this paper, the evolution mechanism of carbide precipitation in the process of plasma cladding of nickel-based alloy on phosphorus removal roll is investigated by the method of phase-field modeling and finite-element coupling. A Ni–Cr–C ternary phase-field precipitation model is developed, and the Ni40A macroscopic solidification process is simulated by ProCAST software, and then the boundary conditions are input into the phase-field model to simulate the carbide precipitation process in the solidification of nickel-based alloy. The simulated atomic diagram shows that the carbide is a core–shell structure, consisting of a Cr-rich core and a C-rich shell, and the carbide morphology changes significantly after coupling the elastic energy. The simulation results are in good agreement with the experimental results, which verifies the feasibility and accuracy of the phase-field method. [ABSTRACT FROM AUTHOR]

In order to investigate the distribution of temperature field in directionally solidified DZ4125 columnar superalloy, and to study the effects of different withdrawl rates on the changes of temperature gradient and mushy zone, the directional solidification processes with withdrawal rates of 3, 5 and 7 mm/min were simulated by ProCAST software. The results show that when the test rod is located in the heating zone, the isotherm is inclined distribution with low outside and high inside. And when the test rod is located in the cooling zone, the isotherm is inclined distribution with high outside and low inside. With the increase of withdrawal rate, the temperature gradient decreases gradually. The shape of the mushy zone depends on the withdrawal rate and the distance from the water-cooled plate. When the withdrawl rate is 5 mm/min, the horizontal state of the solidification front is maintained for a longest time. On this basis, the precision casting experiment of directional solidification test rod is carried out, and the relationship between the shape of liquidus and grain structure is found for castings withdrawn at 3 and 7 mm/min. It is found that when the liquidus is concave and convex, the grain grows towards the center and the surface of the test rod, and the horizontal liquidus can promote the grain growth along the axis of the test rod.

With the aid of virtual prototyping and casting numerical simulation, this work presents the optimization of an injection system used in a non-traditional investment casting process that applies perpendicular centrifugal force to inject the molten metal into refractory plaster molds. In this study, advanced techniques of simulation and production of complex geometries in Computer-Aided Design CAD (Computer-Aided Design) are used in the design of the casting system of a miniaturized simple-cubic cell structure. The cast part has a complex shape profile and needs a high surface finish with strict dimensional tolerance. The alloy used to fill the mold is an aluminum bronze shape memory alloy (SMA). CAD was used to model the part and the proposed models for casting optimization. ProCAST software was used for the numerical simulation of the casting process. Experimental parameters were used as input data for the numerical simulation. The simulation results were analyzed focusing on the identification of defects in the Cu–Al–Mn SMA simple-cubic structures. Different feeding systems have been designed to eliminate the identified defects. Concerning the molten recirculation, the optimal nozzle model has a truncated cone profile, with a larger radius of 6.5 mm, a smaller radius of 2.0 mm and a height of 8.0 mm (called here model 3). Experimental observations from cast SMA parts agree with the simulated results of the optimized nozzle model 3. In addition to the elimination of alloy recirculation with the nozzle optimization in this work, the shrinkage porosity at the upper base of the part was eliminated with the addition of a compensation volume close to the region where porosity is more intense. By exploring the possibilities offered by commercial software, the work contributes to advance the knowledge and application of the non-traditional investment casting process, highlighting its advantages and potential applications. [ABSTRACT FROM AUTHOR]

Because the medium and large-scale Austenitic 304 stainless steel cable protection valve belongs to the cavity valve body, with complex surface shape and structure, there are often some problems in the casting process, such as difficult local heat dissipation and disordered solidification sequence of liquid metal. This will lead to different degrees of shrinkage porosity and shrinkage cavity defects at the ear of the valve body, the bulge at the bottom and the fault of the inner wall of the valve body, and the molding quality is very difficult to control. In order to solve the problem of serious shrinkage porosity and shrinkage cavity in the actual production of valve body parts, the mathematical model was established, and the filling and solidification process of investment casting under traditional gating system was simulated by ProCAST software, the thermodynamic behavior of molten metal in solidification process was analyzed, and the causes of casting defects under traditional methods were found out. A new gating system was designed, and the shrinkage of castings was predicted by Niyama criterion. The experimental results show that the simulation results are consistent with the actual results, and the surface precision of the optimized valve body casting is high and the density is as high as 98.5%. [ABSTRACT FROM AUTHOR]

In this study, the filling and solidification processes of squeeze-casting SiC3D/Al composites were analyzed by the ProCAST simulation software (ver. 2018.0). A practical squeeze-casting experiment was conducted to verify the accuracy of the simulation results. A series of orthogonal experiments were conducted on the initial preheating temperature of various components to identify the optimal parameters in order to achieve better porosity and stress concentration values. According to the results and analyses, the preheating temperature of the mold was the most important determining factor. Under a pouring temperature of 700 °C, mold preheating temperature of 200 °C, and SiC skeleton preheating temperature of 600 °C, the maximum principal stress at the bottom of the products was decreased by about 41.9%, and the shrinkage volume inside the composite was decreased about by about 61.6%. Thus, by adjusting the initial preheating temperature of various components, the squeeze-casting SiC3D/Al composites could achieve better performance and fewer internal defects.

In this study, the filling process, solidification parameters, temperature distribution, and residual stress distribution of gas pressure-infiltrated Al-356/SiC composites were investigated through simulation and experiment. In addition, a series of orthogonal tests was also carried out to precisely demonstrate the preheating temperature, infiltration temperature, and infiltration pressure. After a thorough analysis, the orthogonal tests revealed that the optimal process parameters are as follows: the SiC preheating temperature is 550 °C, the infiltration temperature of the Al-356 alloy is 620 °C, and the infiltration pressure is 8 MPa. The simulation results revealed that pressure had a sharp decrease of ~87% during filling, and the critical pressure was ~0.12 MPa. The velocity decreased with the increase in the filling time, and the average velocity was ~2.60 ms−1. Feasible analysis suggested that critical pressure is ~0.11 MPa and average velocity is ~4.20 ms−1; this difference is attributed to apparent velocity and the Kozeny constant. In the solidification process, shrinkage porosity appeared in the centers of the composites, which is evident with scanning electron microscopy. Moreover, the stress concentration of 171.3 MPa appeared in the composite region connected with the runner, which is the cause of the nucleation of the crack. However, based on the optimum orthogonal parameters and simulative results, the stress concentration was reduced, and crack-free and porosity-free composites were achieved. [ABSTRACT FROM AUTHOR]

Counter pressure casting (CPC) is emerging in the automotive manufacturing industry as an alternative to low-pressure die casting (LPDC) due to its reported superior capabilities in aluminum parts production. This study presents the first comprehensive investigation of how CPC's characteristic feature (applied chamber pressure) influences the fluid flow and heat transport occurring in the process and its effect on casting quality. A large amount of high-quality data was acquired from a commercial CPC process for the production of automotive suspension control arms with two process conditions (standard production and low back-pressure condition). Analysis of the data shows that there are no significant differences between the two process pressure conditions with respect to heat transfer during solidification, as-cast microstructure nor mechanical properties. Generally, in-die measured temperatures exhibited a difference within 10 °C for the two process conditions examined and the ultimate tensile strengths (UTSs) of the samples obtained from castings were within 7% for the two process conditions. Furthermore, there was no measurable difference observed in the Secondary Dendrite Arm Spacings (SDASs) obtained under the two process conditions. However, the implementation of chamber back pressure noticeably reduces the venting rate during the filling stage, leading to 12 s delay in the filling time relative to the low back-pressure condition. A computational modelling methodology, originally developed for LPDC, was applied to simulate the CPC process. The model required only an adjustment to pressure curve to account for the delay of filling owing to the reduced venting rate observed for the higher back-pressure condition. The predicted results were found to correlate well with the measured data, demonstrating that the modelling methodology is broadly applicable to permanent die casting processes.

In order to solve the problems of porosity,slag inclusion,shrinkage porosity,etc.,the influence of low pressure casting process parameters on filling and solidification of the AlSi9Mg gearbox shell was studied.Two different gating systems of the three-dimensional solid model were drawn with Pro/Engineer software,and the influence of pouring temperature,mold temperature and filling pressure on the alloy filling and solidification process during low pressure casting of the AlSi9Mg gearbox shell were studied through the method of numerical simulation using ProCAST software.Based on the experimental results,effective analysis was conducted with orthogonal test table.The result shows that the reasonable process parameters are as follows:Pouring temperature 700 ℃,mold temperature 350 ℃ and filling pressure 45 kPa,and under these process parameters,the defect volume of shrinkage pore of the casting is reduced from 1[KG-*4]537 cm3 to 1[KG-*4]425 cm3.The research on simulation and optimization of low-pressure casting process of AlSi9Mg gearbox lower shell can provide reference for optimization of low-pressure casting process of gearbox lower shell,and has practical application value.

With the aid of virtual prototyping and casting numerical simulation, this work presents the optimization of an injection system used in a non-traditional investment casting process that applies perpendicular centrifugal force to inject the molten metal into refractory plaster molds. In this study, advanced techniques of simulation and production of complex geometries in Computer-Aided Design CAD (Computer-Aided Design) are used in the design of the casting system of a miniaturized simple-cubic cell structure. The cast part has a complex shape profile and needs a high surface finish with strict dimensional tolerance. The alloy used to fill the mold is an aluminum bronze shape memory alloy (SMA). CAD was used to model the part and the proposed models for casting optimization. ProCAST software was used for the numerical simulation of the casting process. Experimental parameters were used as input data for the numerical simulation. The simulation results were analyzed focusing on the identification of defects in the Cu–Al–Mn SMA simple-cubic structures. Different feeding systems have been designed to eliminate the identified defects. Concerning the molten recirculation, the optimal nozzle model has a truncated cone profile, with a larger radius of 6.5 mm, a smaller radius of 2.0 mm and a height of 8.0 mm (called here model 3). Experimental observations from cast SMA parts agree with the simulated results of the optimized nozzle model 3. In addition to the elimination of alloy recirculation with the nozzle optimization in this work, the shrinkage porosity at the upper base of the part was eliminated with the addition of a compensation volume close to the region where porosity is more intense. By exploring the possibilities offered by commercial software, the work contributes to advance the knowledge and application of the non-traditional investment casting process, highlighting its advantages and potential applications.

In order to simulate the casting process of a typical aluminum alloy, a 3 D entity model for a pouring system was used for numerical analysis of the filling and solidification process with ProCAST software. A comprehensive analysis including the change of temperature field, the velocity of filling, the solid phase as well as the location of casting defect, showed that the defects such as shrinkage (cavity) porosity can be reduced effectively with an increase in the mold preheating temperature and the number of vents. This simulation also serves as a theoretical reference for the sake of facilitating casting quality. [ABSTRACT FROM AUTHOR]

The casting simulation software ProCAST was used to achieve the simulation of the filling and solidification process of the high Nb-TiAl alloy impeller investment casting. The influence of the casting and filling process on the filling and solidification characteristics of alloy melt filling, shrinkage cavity and porosity was studied, and the corresponding process was optimized. The casting test and the non-destructive testing analysis of the casting were carried out, and the anatomical analysis of the casting was performed to verify the distribution of the shrinkage cavity and porosity. The mechanical properties of the impeller at room temperature and high temperature were studied using attached test rods. The results show that ProCAST software is more accurate in predicting shrinkage cavity and porosity of the high Nb-TiAl casting, and the process scheme is optimized by simulation and prediction results to avoid the formation of large shrinkage cavity and porosity in casting, only micro shrinkage cavity less than 22 μm is existed in the final casting. All castings are fully filled, with the tensile strength about 580 MPa at room temperature and about 450 MPa at high temperature of 850 ℃.

With the increasing demand for improvements in the temperature capability of aero-engines, there is an urgent need to develop new-generation turbine blade materials. Compared with Ni-based superalloys that have a lower melting point (~1300 ℃), the higher melting point (>1750 ℃), lower mass density (6.6–7.2 g·cm–3), and high-temperature strength of the Nb–Si based alloys make them one of the most promising of the new-generation high-temperature structural materials. A directional solidification process can further enhance the performance of Nb–Si based alloys and lay a foundation for replacing the Ni-based single-crystal superalloys in service at higher temperatures. Accurately determining the thermal property parameters of Nb–Si based alloys and their interfacial heat transfer behavior during solidification is the key to their numerical simulation, which could accelerate the development of Nb–Si based alloys. As yet, however, there has been no research reported in relation to this issue. In this study, we used the directional solidification process of Nb–Si based alloys as the research object and the experimental testing and reverse methods to determine the thermal properties of Nb–Si based alloys and their shells as well as the boundary conditions of the heat transfer coefficient at the interface during the solidification process. To simulate the temperature field of the solidification process of Nb–Si based alloys at different drawing rates, we used ProCAST software. The results reveal that as the withdrawal rate increased from 5 to 10 mm·min−1, the distance between the solid/liquid interface and the surface of the liquid metal tin decreased from 12.1 to 8.2 mm, and the average width of the mushy zone gradually narrowed from 11.5 mm to 10.4 mm. The discrepancy in the spacing of the primary dendrites between the numerical simulation and the actual experimental results at a withdrawal rate of 5 mm·min−1 was within 6%, which verifies the correctness of the temperature-field simulation results. These results provide reference for the determination of the directional solidification casting parameters of turbine blades made of Nb–Si based alloys.

In this study, the filling process, solidification parameters, temperature distribution, and residual stress distribution of gas pressure-infiltrated Al-356/SiC composites were investigated through simulation and experiment. In addition, a series of orthogonal tests was also carried out to precisely demonstrate the preheating temperature, infiltration temperature, and infiltration pressure. After a thorough analysis, the orthogonal tests revealed that the optimal process parameters are as follows: the SiC preheating temperature is 550 °C, the infiltration temperature of the Al-356 alloy is 620 °C, and the infiltration pressure is 8 MPa. The simulation results revealed that pressure had a sharp decrease of ~87% during filling, and the critical pressure was ~0.12 MPa. The velocity decreased with the increase in the filling time, and the average velocity was ~2.60 ms−1. Feasible analysis suggested that critical pressure is ~0.11 MPa and average velocity is ~4.20 ms−1; this difference is attributed to apparent velocity and the Kozeny constant. In the solidification process, shrinkage porosity appeared in the centers of the composites, which is evident with scanning electron microscopy. Moreover, the stress concentration of 171.3 MPa appeared in the composite region connected with the runner, which is the cause of the nucleation of the crack. However, based on the optimum orthogonal parameters and simulative results, the stress concentration was reduced, and crack-free and porosity-free composites were achieved.

The temperature of liquid steel for continuous casting determines the casting speed and cooling conditions. The failure to meet the required casting process parameters may result in obtaining slabs of inconsistent quality. Numerical methods allow for real processes to be modelled. There are professional computer programs on the market, so the results of the simulations allow us to understand the processes that occur during casting and solidification of a slab. The study attempts to evaluate the impact of the superheat temperature on the slab structure based on the industrial operating parameters of the continuous casting machine.

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The influence of blades assembly, i.e., the blade number on the solidification process, heat exchange and grain structure on a directionally solidified Ni-based superalloy DZ125 was investigated by combining the experimental and simulation results. The casting process was simulated thermodynamically by ProCAST software, where the interface heat transfer coefficient was precisely determined by a measurement with thermocouples. There is a good agreement between experimental and simulation results. It was interestingly found that with the number of blades increasing from 6 to 10, due to the decrease in radiation absorption efficiency, the maximum temperature and the heating rate decrease in the mold, during the preheat process. During the withdrawal procedure, increased assembly numbers reduce the radiation exchange from mold to the enclosure, resulting in the decrease in cooling rate and temperature gradient of the blades. At the end of withdrawal, the slower cooling rate of the outside balances the temperature distribution of internal and external surfaces on the rabbet of blade. The interface heat transfer coefficient (IHTC) values of DZ125 casting system were investigated by inverse method. Then, a series of assembly blade groups were designed and being cast and calculated. Values of IHTC are proved to be suitable for different assembly groups of casting in this case. Based on simulation and experimental results, it was interestingly found that: In the preheating process, with the number of blades increased, the maximum temperature on the mold becomes lower and the heating rate becomes slower, which result from the decrease in radiation efficiency between the mold and graphite heater. During the withdrawal, increasing assembly blade number reduced the radiation exchange from the mold to the enclosure, and it results in the cooling rate and temperature gradient on the blades getting decreased. At the end of withdrawal, the slower cooling rate leads to the temperature distribution maintaining uniformity for internal and external surfaces on the rabbet of the blade. [ABSTRACT FROM AUTHOR]

Many types of alloys can be cast in graphite molds. The advantage of using graphite molds is that graphite has a higher thermal conductivity than steel and provides a higher alloy cooling rate. In this work, the solidification conditions in graphite and steel molds are compared. Cylindrical ingots of A356 aluminum and AZ81 magnesium alloys were cast into steel and graphite molds, and the temperature was recorded by thermocouples positioned in both the ingots and the molds. Using the error function, which is a measure of the difference between the experimental and simulated temperatures, the interfacial heat transfer coefficient (IHTC) versus the ingot surface temperature curves were obtained. The peak IHTC for ingot casting in the graphite mold was 2–3 times higher than that for the steel mold for both alloys. The solidification time and cooling rate for the solidification of the A356 and AZ81 ingots with varied sizes in the graphite and steel molds were calculated based on the simulation results. The duration of the solidification process in the steel mold was nearly two times longer than that for ingots in the graphite mold. The cooling rate in the graphite mold was nearly 1.5–2 times higher than that in the steel molds. [ABSTRACT FROM AUTHOR]

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Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The large warping deformation at platform of turbine blade directly affects the forming precision. In the present research, equivalent warping deformation was firstly presented to describe the extent of deformation at platform. To optimize the process parameters during investment casting to minimize the warping deformation of the platform, based on simulation with ProCAST, the single factor method, orthogonal test, neural network and genetic algorithm were subsequently used to analyze the influence of pouring temperature, shell mold preheating temperature, furnace temperature and withdrawal velocity on dimensional accuracy of the platform of superalloy-DD6 turbine blade. The accuracy of investment casting simulation was verified by measurement of platform at blade casting. The simulation results with the optimal process parameters illustrate that the equivalent warping deformation was dramatically reduced by 21.8% from 0.232295 mm to 0.181698 mm.

The cooling conditions of a slab during continuous casting of steel have an impact on the crystalline structure formation. Numerical methods allow real processes to be modelled. Professional computer programs are available on the market, so the results of their simulations allow us to understand the processes that occur during the casting and solidification of the slab. The study attempts to evaluate the impact of the intensity of the secondary cooling on the chilled zone size. The calculations show the differences in the structure of a slab cast with various speeds while maintaining industrial cooling parameters during operation of a continuous casting machine.

The analysis of influence of mould withdrawal rate on the solidification process of CMSX-4 single crystal castings produced by Bridgman method was presented in this paper. The predicted values of temperature gradient, solidification and cooling rate, were determined at the longitudinal section of casting blade withdrawn at rate from 1 to 6mm/min using ProCAST software. It was found that the increase of withdrawal rate of ceramic mould results in the decrease of temperature gradient and the growth of cooling rate, along blade height. Based on results of solidification parameter G/R (temperature gradient/solidification rate), maximum withdrawal rate of ceramic mould (3.5 mm/min), which ensures lower susceptibility to formation process of new grain defects in single crystal, was established. It was proved that these defects can be formed in the bottom part of casting at withdrawal rate of 4 mm/min. The increase of withdrawal rate to 5 and 6 mm/min results in additional growth of susceptibility of defects formation along the whole height of airfoil.

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The ISO 22674 standard categorizes metallic materials that are suitable for dental appliances and restoration fabrication. Nickel, cadmium, and beryllium are classified as hazardous elements in this international standard. However, many alloys containing nickel and beryllium are used in dentistry as biomedical metallic materials. Numerous studies on the toxicity of nickel and beryllium have led to serious doubts about the biological reliability of these alloys. Titanium therefore attracts great interest due to its potential use in dental prostheses. Commercially pure titanium has biocompatibility, low density, great corrosion resistance, and mechanical strength at room temperature. In spite of its numerous desirable properties, it is hard to cast titanium because of its high melting temperature. In this study, the microstructure and castability of binary Ti–Mo alloys (2%, 4%, 6%, 8%) was investigated using numerical methods to evaluate their potential use in dentistry. ProCAST software was used to model the casting behavior. [ABSTRACT FROM AUTHOR]

The temperature of liquid steel for continuous casting determines the casting speed and cooling conditions. The failure to meet the required casting process parameters may result in obtaining slabs of inconsistent quality. Numerical methods allow for real processes to be modelled. There are professional computer programs on the market, so the results of the simulations allow us to understand the processes that occur during casting and solidification of a slab. The study attempts to evaluate the impact of the superheat temperature on the slab structure based on the industrial operating parameters of the continuous casting machine. [ABSTRACT FROM AUTHOR]

The values of thermophysical properties obtained from the experimental research, and those that were calculated with thermodynamic databases, are crucial parameters which were used in the numerical modelling of the steel solidification process. This paper presents the results of research on the impact of specific heat and enthalpy, along with the method of their implementation, on temperature distribution in the primary cooling zone in the continuous steel casting process. A cast slab – with dimensions of 1100 mm and 220 mm and a S235 steel grade – was analysed. A mould with a submerged entry nozzle (SEN), based on the actual dimensions of the slab continuous casting machine, was implemented. The research problem was solved with the finite element method using the ProCAST software package. Simulations were conducted using the “THERMAL + FLOW” module.

This manuscript presents an advanced modeling methodology developed to accurately simulate the temperature field evolution in the die and wheel in an industrial low-pressure die casting (LPDC) machine employed in the production of A356 automotive wheels. The model was developed in the commercial casting simulation platform ProCAST for a production die operating under production conditions. Key elements in the development of the model included the definition of the resistance to heat transfer across the die/casting interfaces and die/water-cooling channel interfaces. To examine the robustness of the modeling methodology, the model was applied to simulate production and non-production process conditions for a die cooled by a combination of water and air-cooling (Die-A), and to a second die for a different wheel geometry (Die-B) utilizing only water cooling for production conditions. In each case, the model predictions with respect to in-die and in-wheel temperature evolution were compared to industrially derived thermocouple (TC) data, and were found to be in good agreement. Once tuned to the process conditions for Die-A operating under production conditions, no further tuning of the die/casting interface resistance was applied. Additionally, the model results, in terms of the prediction of pockets of solid encapsulated liquid, were used to compare to x-ray images of wheels. This comparison indicated that the model was able to predict clusters of porosity associated with encapsulated liquid with an equivalent radius of ~27 mm.

In this work, a plant trial was conducted on an industrial low pressure die casting (LPDC) manufacturing process for the production of aluminum alloy wheels. Various types of data have been acquired, including extensive measurements of temperature at different locations (die, wheel and cooling channels), pressure in cooling channels and size/location of shrinkage porosity in the produced wheels. Moreover, two process conditions were tested in the trial—one was the standard production process condition and the other was designed to generate shrinkage porosity in wheels by altering the die temperature. The large amount of quantitative data acquired in this study helped us to understand the key transport phenomena occurring in the process, which include: (1) a thorough picture of the evolution in temperature at a large number of discrete locations in the die and the casting; (2) the dynamic and complicated heat transfer in the cooling channels both water-on and water-off stages, associated with boiling water heat transfer. This paper (Part I) presents the results and findings obtained from the process characterization. The follow-on paper (Part II) will introduce the developed modeling methodology based on the data produced from this work.

This paper presents the findings of research conducted concerning the determination of thermal boundary conditions for the steel continuous casting process within the primary cooling zone. A cast slab - with dimensions of 1100 mm×220 mm - was analysed, and models described in references were compared with the authors’ model. The presented models were verified on the basis of an industrial database. The research problem was solved with the finite element method using the ProCAST software package.

The study presents the findings of research concerning the possibilities for application of parallel processing in order to reduce the computing time of numerical simulations of the steel continuous casting process. The computing efficiency for a CCS model covering the mould and a strand fragment was analysed. The calculations were performed with the ProCAST software package using the finite element method. Two computing environments were used: the PL-Grid infrastructure and cloud computing platform.

The piercing of aluminium ingots (made by permanent mold gravity casting) is done in a Mannesmann rolling mill with supporting shoe using plugs of various shapes with a spherical working part: an entire plug, a plug with cavity, and a hollow plug. The calibrating segments of the plugs have identical diameters. The piercing is carried out at an ingot temperature of 400°C. The influence of the plug shape on the variation in the outer hollow shell diameter and wall thickness along the shell length, as well as shell density over the length, is investigated. Hollow shells were cut into 15 equal rings to measure density using hydrostatic weighing. Experimental investigations are simulated with the help of the finite-element method (FEM) computer software. Ingot fabrication by permanent mold gravity casting is simulated using the ProCAST software and piercing—using the QForm software. The variation in the hollow shell diameter, wall thickness, and shell density along the length is also evaluated by computer simulation. Experimental and simulation data are compared to verify the adequacy of acquired models in the QForm. The difference in density does not exceed 2% and, for hollow shell dimensions, 20%. These results make it possible to establish the influence of the piercing plug shape on the accuracy of the shells and their density. It is most preferable to use a hollow plug or a plug with a cavity from the viewpoint of dimension accuracy of fabricated shells. Each of these piercing schematics makes it possible to densify the entire hollow shell volume to the true density, except for the near-edge domains, where the density is lower by 1%. [ABSTRACT FROM AUTHOR]

Predicting the misrun formation in thin-walled castings of magnesium alloys is a critical task for foundry. The computer simulation of casting processes can be used to solve this problem. Adequate results of simulation can be attained in the presence of the correct thermal properties of the alloy and a mold in a wide temperature range, interface heat-transfer coefficient between the casting and a mold, and the critical solid fraction (at which the melt flow in a mold is stopped). In this work, the interface heat-transfer coefficient between the ML5 (AZ91) magnesium alloy and a no-bake sand mold is found by comparing simulation spiral test lengths with experimental spiral test lengths under the same pouring conditions. Its values above the liquidus temperature are hL = 1500 W/(m2 K) at pouring temperatures of 670 and 740°C and hL = 1800 W/(m2 K) at 810°C. Below the solidus temperature, hS = 600 W/(m2 K). The critical solid fraction for the ML5 (AZ91) magnesium alloy was also determined for no-bake mold casting (with a cooling rate of ~2 K/s)—its value was 0.1-0.15. The critical solid fraction is refined by comparing the position of misruns by the results of simulation and in an actual "Protective cap" ML5 (AZ91) alloy casting poured into the no-bake mold. Castings are poured at temperatures of 630 and 670°C, and the critical solid fraction is 0.1 in both cases. [ABSTRACT FROM AUTHOR]