Squeeze Casting Process Design And Numerical Simulation Of Aluminum Alloy Support With Large Wall Thickness Difference

Automobile lightweight is the trend of automobile development in the world.Under the condition of ensuring automobile safety and strength,it is of great significance for energy conservation and environmental protection to reduce vehicle quality,improve vehicle power,reduce exhaust pollution and reduce energy loss.ADC12 Aluminum alloy has low density and high specific strength,It is widely used in the lightweight of auto parts.With the rapid development of CAE/CAD in molding process parameter optimization and die design,the development cycle of auto parts is significantly shortened and the quality is significantly improved.In the production process,aluminum alloy castings with large wall thickness difference often have shrinkage cavity and porosity defects.The quality of castings produced by high pressure die casting can not meet the application requirements.Indirect squeeze casting can produce castings with large wall thickness difference and complex shape.In this paper,the load-bearing support of a vehicle is taken as the research object,the ProCAST numerical simulation is embedded into the design process of gating system and die,and the optimal process parameters are obtained.The results show that the casting produced by this design method has good quality and meets the application requirements.In this paper,the three-dimensional drawing software is used to model the parts and analyze the manufacturability.The forming method adopts indirect squeeze casting,and the equipment model is selected by calculating the bulging force in the casting process;Then the critical speed of the inner gate and the defects of different gating systems are simulated and analyzed by ProCAST software,and the optimization scheme is put forward;Then,the effects of different process parameters on the temperature field,stress field and defects of liquid metal are simulated and analyzed,the optimal process parameters are selected,and the squeeze pin process is designed where the feeding system can not be fed;Finally,experimental verification is carried out.Through simulation analysis,it is determined that the critical filling speed of the inner gate in the support is 0.15 m/s,the filling is stable and will not be involved in the oxide film.When the pressure,pouring temperature and mold preheating temperature are 150 bar,700℃ and 200℃ respectively,the shrinkage and porosity defects of the casting are the smallest,which are concentrated in the boss.The designed activation time of the squeeze pin is 1.1 s and the removal time is 9.5 s.After local extrusion,the shrinkage and porosity defects of the boss are eliminated.Through the test and verification of the best process parameters,the surface of the casting is smooth and free of cracks,There is no obvious shrinkage defect inside.When the pressure is 150 bar,the tensile strength of the casting is 293.2 MPa,the elongation after fracture is 3.7%,and the quality meets the service requirements.