(1. 哈尔滨工业大学材料科学与工程学院，哈尔滨 150001；
2. 哈尔滨工业大学机电工程学院，哈尔滨 150001)
摘 要: 采用ProCAST软件模拟了A356.2铝合金汽车轮毂在局部增压铸造技术下的充型和凝固过程，探究了铸件的温度场、缺陷分布和应力场。结果表明：铸件基本符合顺序凝固，但是部分区域出现了热节；缩松、缩孔缺陷主要分布在轮辐与轮辋交界处、轮辐与中间毂交界处以及轮辋某些区域；合适的浇注温度、模具温度以及局部机械加压可以有效地减少缺陷；等效应力大小由热应力与机械应力共同决定。正交试验优化后的压铸参数为：浇注温度tpouring710 ℃，上模温度tupper die340 ℃，边模温度tside die360 ℃，下模温度tlower die400 ℃，风压0 MPa，机械压力1.4 MPa。在此条件下由试验获得的轮毂缺陷最少，力学性能最好。
关键字: A356.2 铝合金；局部增压铸造；数值模拟；温度；压力
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:ProCASTsoftware was used to simulatethe filling and solidification process ofA356.2 aluminum alloy automobile hub through local pressurizationcasting technology, and temperature field, defects distribution and stress field were investigated. The results show that the solidification is basically in sequence, but thermal centers appear at some regions.Shrinkageporosities defects are mainly distributed in the spoke/rim junction, spoke/center hub junction, and the partial region of rim. Proper pouring temperature, moulding temperature andlocal mechanical pressurization can eliminate the defects effectively. The effective stress is codetermined by the thermal stress and mechanical stress.The die-casting parameters optimized after the orthogonal test are as follows: pouring temperature of 710 ℃, upper dietemperature of 340 ℃, side die temperature of 360 ℃,lower die temperature of 400 ℃, wind pressure of 0 MPa, and mechanical pressure of 1.4 MPa.Under the optimized conditions, the hub obtained from the test has the least defects and the best mechanical properties.
Key words: A356.2 aluminum alloy; localpressurizationcasting; numerical simulation; temperature; pressure
