应力时效对2E12铝合金的力学性能和微观组织的影响

Effect of stress aging on mechanical properties and microstructures of 2E12 aluminum alloy

采用力学性能试验机、透射电子显微镜(TEM)、应力时效炉等手段研究时效拉应力对2E12铝合金的力学性能和微观组织的影响,并分析应力对2E12铝合金的作用机理。结果表明:外加应力能提高2E12铝合金的强度,增大合金各向异性的差异;外加应力能促进S相的析出,并产生明显的应力位向效应;应力时效能使2E12铝合金的无沉淀析出带变窄,阻止晶界沉淀相的连续析出;应力时效为控制高强铝合金的各向异性提供了一种新方法。

The influences of tensile stress aging on the mechanical properties and microstructure of 2E12 aluminum alloy were investigated by means of mechanical tests, transmission electronic microscopy （TEM） and stress aging furnace. The effect mechanic of tensile stress on 2E12 aluminum alloy was analyzed. The results show that the external stress during aging improves the ultimate strength and increases the ultimate strength anisotropy of 2E12 aluminum alloy. The external stress can enhance thq, precipitation of S phase and induce the preferred orientation of precipitated S phase. Under the external stress aging, the precipitation free zone （PFZ） is narrowed and the distribution of those precipitates changes from chains to non-continuous ones. The stress aging provides a tool to control the anisotropy in highstrength aluminum alloys.