Research On Quick Casting Process And Numerical Simulation Of Complex Parts Based On Additive Manufacturing

Quick Casting is a new process to produce castings rapidly,which is made up of modern RP technology and traditional casting.The new process is mainly aimed at the complicated structure and difficult metal casting in aerospace and automobile power industries.Compare RP technology with traditional casting,RP technology has some advantages below.It can shorten production of cast molding cycle,improvement of precision and wide variety of applied castings.The diffuser in this study is made by cast aluminum alloy ZL101.The process of casting filling and solidification directly displayed on the computer from the numerical simulation of casting process,we can forecast the possible casting defect area and find out the optimal scheme and parameters of the foundry technology.Then we use the SL prototype of diffuser based on Stereo Lithography technology which is one of 3D Printing technology to manufacture diffuser casting,the next processing steps include the coating of refractory on the SL prototype,drying of the shell,dewaxing and baking of mold shell in high temperature to get the harden mold shell which has heat-resistant and certain strength.Finally pour the molten metal into the mold shell by low pressure casting equipment to get the diffuser casting.The quick casting of low pressure and investment casting for diffuser is realized.Firstly in this study,we use three-dimensional model of the diffuser initial gating system by UG software,the scheme of bottom filling with 4 ingates have been set up.And then numerical simulation of mold filling and solidification process after mesh division and setting of boundary conditions by ProCAST software.Optimization of gating system by some factors such as flow field,temperature field,shrinkage porosity distribution and so on.The rationality of the 8 ingates scheme after optimization is illustrated by the simulation again.Secondly,there are three levels and three factors are selected based on pouring temperature,the pressure rate and the preheating temperature of the mold by calculating and selecting.A comprehensive test of three factors and three levels has been developed,and then all 27 groups of process parameters are numerically simulated.The optimal process parameters were obtained by the simulation results of filling,solidification and stress field,the pouring temperature 720?,the pressure rate 0.0015MPa/s,the preheating temperature of the mold 350?.Finally,We apply the optimal process parameter to the rapid casting process of the diffuser,Combining the SL prototype of the diffuser made by 3D printing technology and wax gating system,we finally obtain the diffuser casting without defects through shell preparation,low pressure pouring,shelling cleaning,nondestructive testing and other links.The rapid casting process of low pressure and investment casting based on SL for this kind of diffuser casting is realized.