Numerical Simulation And Process Optimization Of Low Pressure Die Casting On ADC12 Aluminum Alloy Engine Front Case Shell

In this paper,the object of our research is a front engine case shell of automobile engine,and its material is ADC 12 aluminum alloy.In this paper,Pro-CAST casting simulation software was used to simulate the casting process.In order to solve the casting forming problems,this paper performed heat treatment experiments and mechanical performance tests on ADC 12 aluminum alloy samples to determine the most appropriate heat treatment processes,and formulated a practical casting process by design,calculation and optimization.In this paper,the mixed gating system of the kiss sprue runner and the center sprue runner was designed by the low pressure-sand casting method.With the riser and air vent,the process parameters such as the quality casting requirements,the dimensional tolerance and the weight tolerance etc.were determined.According to the theoretical formula and practical experience,the optimized parameters of the casting process are 720 ? for pouring temperature,15.6 kPa for rising pressure,12 s for rising time,25 kPa for filling pressure,4 s for filling time,33 kPa for skull supercharging pressure,2 s for skull supercharging time,3 s for skull holding time,50 kPa for crystallizing pressure,5 s for crystallizing time,and 240 s for crystallizing holding time.The simulation results showed that optimized gating system and low-pressure casting process promoted the stability of filling process,the better sequence of solidification and less shrinkage porosity of the casting.In the paper,the sand mold and core was calculated by optimized front case shell casting and made by 3D printing.The melting and heat treatment of ADC 12 aluminum alloy were tested in three different kinds of heat treatment processes.The Brinell hardness test was carried out before and after the heat treatment of ADC 12 materials.The results showed that the hardness of ADC 12 aluminum alloy after the heat treatment process 2 was 85.87HBS,which met the technical requirements.The tensile strength of 187.123 MPa and the elongation of 2.19%were carried out on the ADC 12 aluminum alloy treated with Process 2,which also met the industry standard and quality requirements of castings.By mechanical properties test,the specific heat treatment technology of ADC 12 aluminum alloy was determined:solution temperature was 520 ?,solution time was 6 h,artificial aging temperature was 170 ?,artificial aging time was 10 h.The chemical composition analysis,XRD analysis and metallographic analysis results showed that the ADC 12 aluminum alloy after heat treatment had good microstructure and high comprehensive mechanical properties.In this paper,a complete casting process card was developed based on numerical simulation results and heat treatment experiments.And the Engine front case shell casting was manufactured using the optimized casting process card.The appearance test results showed that the casting had complete structure and high surface quality.Meanwhile the fluorescence detection,X-ray detection and pressure leak detection results showed that the casting can meet the corresponding national standards and technical requirements.