Numerical Analysis And Die Design Based On Aluminum Alloy Wheel Low Pressure Casting

The traditional low-pressure casting process development,improvement and optimization need to repeatedly trial,analysis to finalize the process plan,resulting in a direct extension of the product's production cycle.At present,the research on aluminum alloy low pressure casting mainly focuses on the numerical simulation of mold filling process and mold temperature field.According to the experimental results,the quality of mold and casting process is qualitatively analyzed,without quantification to specific index.Using the new mathematical model and finite element analysis method,the design and optimization of low pressure casting process and mold are carried out.The main contents and results are as follows:Aiming at the aluminum liquid flow and heat transfer in the process of low pressure casting of aluminum alloy w heel,a mathematical model describing the casting process is established.The combination of temperature rise method and equivalent heat capacity method can effectively avoid the system deviation caused by the equivalent heat capacity method when passing through the phase line and make use of the advantage of the small amo unt of temperature rise method.The reasonable approximation and assumption of the mathematical model of low pressure casting solidification process are carried out.The finite element software was used to simulate the temperature field and the stress field of the aluminum alloy die-casting process,and the defects such as entrained gas,slag inclusion and shrinkage cavity were analyzed.The temperature and stress curves of the mold cavity under the mold were extracted to judge the thermal shock and fatigue deformation of the mold,which provided the data support for the response surface analysis and optimization.Combined with the actual situation and process parameters of die in low-pressure die-casting,the central composite test method was used to test t he main factors affecting the die stress and die quality,and the response surface and parametric equations of each influencing factor to the maximum stress and die quality of die was obtained.In order to reduce the mold weight / low thermal stress,an optimized model of low-pressure die-casting wheel hub was established.The Pareto optimization solution set was obtained by NSGA-?.Based on this,the mold structure and die-casting process were modified.The revised mold and process parameters were re-simulated and compared with before to analyze whether the casting defects and the maximum stress of the mold have been improved.