工艺参数对汽车用铸造新型合金性能的影响

Influences of Process Parameters on Performance of New Casting Alloy for Automobile

采用不同的工艺参数进行了新型车用镁合金Mg-5Al-1.5Zn-0.5Ce-0.5Sr的低压铸造,并研究了工艺参数对其显微组织、物相组成和力学性能的影响。结果表明,在浇注温度680~730℃、充型时间10~22 s时,随浇注温度的增加或充型时间的延长,合金晶粒先细化后粗化,平均晶粒尺寸先减小后增大,抗拉强度、屈服强度和断后伸长率均先增大后减小;但对合金的物相组成、拉伸断裂机制无明显影响。优化的工艺参数为浇注温度705℃和充型时间16 s。

The low pressure casting of new Mg-5Al-1.5Zn-0.5Ce-0.5Sr magnesium alloys for automobile was conducted by using the different process parameters. The effects of process parameters on microstructure, phase composition and mechanical properties were studied. The results show that during the pouring temperature of 680-730℃ and the filling time of10-22 s, with the increase of pouring temperature or the extension of the filling time, the grain of the alloy is first refined and then coursen, the average grain size decreases first and then increases, the tensile strength, yield strength and elongation increase first and then decrease. But it has no obvious influence on the phase composition and the tensile failure mechanism of the alloy. Optimization process parameters are pouring temperature of 705℃ and the filling time of 16 s.