SCR成形Al-1.5Mg-0.3Sc合金线材的组织与性能

采用单辊搅拌冷却技术(SCR)制备Al-1.5Mg-0.3Sc(质量分数,%)合金线材,对比相同成分常规铸造工艺制备的合金,对SCR成形合金线材组织与性能进行了研究.结果表明:SCR成形Al-1.5Mg-0.3Sc合金的晶粒较常规铸造工艺制备合金的晶粒细小;常规铸造工艺制备的Al-1.5Mg-0.3Sc合金,金相试样腐蚀后,在合金晶界处出现黑色的、结构不规则的层片状、有弓形边界的Al3Sc沉淀物;SA合金线材520℃在线固溶、320℃时效3 h,抗拉强度为304 MPa,延伸率为18.9%,合金线材具有较高的强度和良好的塑性.

Microstructure and Property of Al-1.5Mg-0.3Sc Alloy Formed by SCR Technology

The SCR(Shearing-Cooling-Rolling) and conventional casting technology were compared in the preparation of Al-1.5Mg-0.3Sc(wt%), with the effect of trace of Sc addition on the microstructure and property of Al-1.5Mg-0.3Sc(wt%) alloy wire formed by SCR technology investigated. The results showed that the grain of SCR-formed alloy wire is smaller than that of the alloy wire formed conventionally. The latter, after its specimen was metallographically etched, presents the back and irregular lamellar structure at its grain boundaries with some Al3Sc precipitates found at arc boundaries. But, the former, when its specimen was solid solution at 520°C and aged at 320°C for 3 h, its tensile strength is 304 MPa with an elongation 18.9%. It revealed that the SCR-formed alloy wire has higher strength and plasticity.