Research On Crystallization Solidification Process And Formation Mechanism Of Pore Defect For Complex Aluminum Alloy Die Casting

The base of this topic research is one of the important parts of the car circuit. The surface of the part can’t exist flash、burr and crack, the internal can’t exsit some defects such as pore. For the above reasons, aluminum alloy cold chamber die casting method is used for it’s production. The production practice proved that the key to improve the quality of this part is the design of die casting molding process and the determination of die casting technological parameters. The design of the molding process mainly includes the design of joint face、gating system and exhaust system. The technological parameters mainly includes pouring temperature、filling speed and molds preheating temperature.Through the analysis about die casting in study, five kinds of casting solutions were designed. On the basis of reviewing relevant data and combining with specific production experience then the initial value of technological parameters were determined. Using numerical simulation software AnyCasting to fill the die casting and found some problems existing in current structure design thus improved it. By analyzing the simulation results then the best casting solution was choosed. Using the control variable method, and determining the optimal value range of the technological parameters. Then I designed a three factors and three levels orthogonal experiment, and selected residual melt module and composite defect parameter as quantitative parameter to investigate the experimenal results, at last the best die casting technological parameters combination were got. Then the crystallization was emphatically analyzed for the solidification process of this combination, and the possible position and cause were predicted for pore. The researches show that the probability of all kinds of defects have been obviously reduced under the optimal die casting technology parameters. Using the optimized process parameters for experimental die casting and the high quality castings with few defects were got. For the purpose of intuitive analysis and research,I used wire-electrode cutting to cut casting organization then the microstrcture was observed and found that the defect area of the sotware simulation and the actual defect position of casting is unanimous.In the study of cooperation with factory, I also designed a set of hot chamber zinc alloy die casting process program under the request of factory and used AnyCasting to simulate it. At last, the best die casting technological parameters combination was got.Research shows that numerical simulation analysis can improve die casting solution and process parameters before the actual die casting production. And it could guide the similar base complex die casting molding process design and production thus improve the yield and economic benefit of die casting.