以新型机加工材料Al-Si-Mg合金铸件为研究对象,在Instron5500电子万能材料试验机上进行超塑性拉伸试验,研究了合金在不同温度和应变速率下的超塑性变形及合金微观组织。结果表明,随着温度升高,合金的伸长率和真应力不断增加,应变速率敏感指数也随着增加,合金流动活化能不断减小,合金超塑性变好;在合金挤压过程中,铸态合金中含有纤维球状的共晶硅颗粒,随着热处理的不断进行,共晶硅颗粒不断细化且均匀分布,横向截面的共晶硅颗粒比纵向截面的共晶硅颗粒密集,经过人工时效处理后,合金中共晶硅颗粒不断增加,强度不断增加,伸长率逐渐减小。 With the new machined material Al-Si-Mg alloy casting as the research object, the superplastic tensile test was carried out on the Instron5500 electronic universal material testing machine to study the superplastic deformation and the alloy microstructure of the alloy under different temperature and strain rate. The results show that as the temperature increases, the elongation and true stress of the alloy increase, the strain rate sensitivity index increases with the increase of the activation energy of the alloy flow, and the superplasticity of the alloy becomes better. During the extrusion process, The as-cast alloy contains fibrous spherical eutectic silicon particles. With the continuous heat treatment, the eutectic silicon particles are continuously and uniformly distributed. The eutectic silicon particles in the transverse cross section are more dense than the eutectic silicon particles in the longitudinal cross section. After artificial Aging treatment, the alloy eutectic silicon particles continue to increase, increasing strength, elongation decreased.