摘要
针对镁合金类大型复杂铸件在进行T6水淬热处理过程中易变形甚至开裂的问题,优化了一种基于空冷的T6热处理工艺。采用Mg-10Gd-3Y-0.5Zr合金和低压砂型铸造工艺制备了某型号舱体,并切取试样进行固溶和时效后均空冷的T6热处理工艺优化研究,获得最佳工艺为525℃×12h+250℃×12h,对应的最高力学性能为:屈服强度247MPa、抗拉强度346MPa、延伸率3.4%。另外,随着时效温度和时效时间的增加,合金的断裂机制也由欠时效态的穿晶解理断裂转变为峰时效态的穿晶和沿晶混合型准解理断裂。
In order to avoid crack failures tend to appear in complicated structural components with thin walls when using traditional water cooling method after solid solution and aging heat treatment, the T6 heat treatment process of the low-pressure sand-cast Mg-10Gd-3Y-0.5Zr alloy which was taken air cooling method after solid solution and aging treatment was optimized. The results showed that the optimal T6 heat treatment under solution and air-cooled condition was 525℃×12h＋250℃×12h, the yield strength, ultimate strength and elongation was 247 MPa, 346 MPa and 3.4%, respectively. In addition, with the increase of aging temperature and time, the fracture mode of T6 treated Mg-10Gd-3Y-0.5Zr alloy changed from transgranular cleavage fracture to mixture of transgranular and intergranular quasi-cleavage fracture.
出处
《航天制造技术》
2015年第6期1-6,共6页
Aerospace Manufacturing Technology
