Optimization of the investment casting process and defect control for variable cross-section components of TC4 alloy
In this study,the centrifugal investment casting process was optimized using ProCAST soft-ware based on an orthogonal experiment for TC4 alloy variable cross-section components.Simultan-eously,the mold filling and solidification behaviors of the castings were investigated in detail,and the quality and mechanical properties of the castings were characterized.The results show that a small amount of shrinkage porosity is discretely distributed in the middle and bottom of the casting,while a large concentration is discretely distributed at the top.The formation of isolated liquid phase zones is the main reason for the shrinkage porosity,and the termination of melt metal flow exhibits the charac-teristics of a narrow crystallization temperature range.At the same time,the stress concentration mainly occurs at the connection between the inner sprue and the casting,and the major cause of it is the large structural change.The internal quality and dimensions of the casting were characterized,and it was dis-covered that there is no shrinkage porosity,the casting dimensions better satisfy the design require-ments,and there is no visible deformation.The room-temperature tensile strength(UTS)of the hot iso-static pressing(HIPed)castings is 953.5 MPa,the yield strength(YS)is 835.0 MPa,and the elongation(EL)is 10.0％,which can better meet the actual service demands.
TC4 alloyvariable cross-section componentsinvestment castingProCAST numerical simulationdefect control
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