A Review Paper on Simulation of solidification process in casting and optimization of Riser

ABSTRACT Casting solidification is actually the transformation of liquid phase to solid phase with the liberation of latent heat of fusion. During this metallurgical process, it induces casting defects like shrinkage, porosity and hot tears. To eradicate and eliminate these problems, accurate casting design and proper design of gating system is necessary. This can be predicted and designed by means of computer simulation of casting solidification. This review paper discusses about the simulation process of casting solidification, better understand the temperature history of the solidifying casting and hence to identify the hot spot region with the aid of obtained time-temperature contours. A technique to determine the thermal boundary conditions existing during the solidification of metallic alloys in the investment casting process is presented. Quantitative information about these conditions is needed so that numerical models of heat transfer in this process produce accurate results. In particular, the variation of the boundary conditions both spatially and temporally must be known. The method used involves the application of a new inverse heat conduction method to thermal data recorded during laboratory experiments of aluminum alloy solidification in investment casting shell molds. The resultant heat transfer coefficient for the alloy/mould interface is calculated. An experimental program to determine requisite mould thermal properties was also undertaken. It was observed that there is significant variation of the alloy/mould heat transfer coefficient during solidification. It was found that both melting commencement and completion were increased with increasing heating rate, in contrast inverse behavior was observed during cooling.