Numerical Simulation And Optimization Of Quick Casting Process Based On Rapid Prototyping For Turbine Housing

The turbine housing in this study is made by nickel-base super alloy K418.From the numerical simulation of casting process,process of casting filling and solidification directly displayed on the computer, we can forecast the possible casting defect area and optimize foundry technology.Then we use the RP prototype of turbine housing based on Rapid Prototyping to manufacture turbine housing castings,the processing steps include the coating of refractory on the RP prototype and baking of mold shell with the RP prototype in high temperature to get the harden mold shell which has heat-resistant and certain strength,pour the molten metal into the mold shell by Quick Casting to get the turbine housing castings.In this study,we use three-dimensional model of the turbine housing by Pro/E software, develop three preliminary process programs including deluge gate system,step gating system, top-three-point system,model the gating system of three programs respectively and then mesh it.Set the boundary conditions of casting in the ProCAST software and then simulate the castings filling and sodification.According to the simulation results,the reasonable gating system was top-three-point system.Test the deluge gate system and top-three-point system processing programs to verify the rationality of simulation by the ProCAST.The castings defects of the deluge gate system emerge in the turbine housing cast which is similar with the simulation result.To avoid such defects,optimizing and numerical simulating of the casting process parameters of the top-three-point system is done to get the better castings.Based on the reasonable gating system by ProCAST,the casting process parameters including pouring temperature and initial temperature of the mould shell is changed, then simulation of the casting filling and solidification is done to get the better process parameters. Effect of pouring temperature and initial temperature of mold shell on casting defect were analyzed respectively through orthogonal test,the better simulation result was got while pouring temperature is at 1400℃,initial temperature of mold shell is at 1120℃.the intact castings of turbine housing was got.