电场固溶处理对2219铝合金第二相及力学性能的影响

Effects of Solution Treatment in Electric Field on Second Phase and Mechanical Properties of 2219 Aluminum Alloy

2219铝合金中存在着大量的粗大第二相(Al2Cu)粒子是导致其强韧性偏低的重要因素。采用扫描电镜(SEM)、透射电镜(TEM)、拉伸测试等材料测试分析手段研究了电场固溶处理新工艺对2219铝合金第二相及力学性能的影响。结果表明:在固溶处理过程中施加12 kV/cm的电场能提高铜元素的短程扩散速度,促进粗大第二相的溶解。与未施加电场相比,电场固溶处理使合金中的粗大第二相的含量降低,粗大第二相的溶解使铝基体中铜元素含量得以提升,进而使后续时效过程中合金弥散相的析出驱动力得以提高,时效后θ’相更细小致密。经过电场固溶处理后,合金的综合力学性能得到改善,合金的伸长率提升较为显著,从13.3%提升至15.6%。

The presence of a large number of coarse second-phase(Al2Cu)particles in 2219 aluminum alloy is an important factor contributing to its low strength and toughness.The effects of the new process of electric field solution treatment on the second phase and mechanical properties of 2219 aluminum alloy were studied by means of SEM,TEM and tensile tests.The results show that applying an electric field of 12 kV/cm during the solid solution treatment can improve the short-range diffusion rate of copper elements,and promote the dissolution of coarse second phase.Compared with the unapplied electric field,the content of the coarse second phase in the alloy is reduced by the electric field solution treatment.The dissolution of the coarse second phase increases the content of copper in the aluminum matrix.Furthermore,the precipitation driving force of the alloy dispersion phase increases during the subsequent aging process.The phase is smaller and denser after aging.After the electric field solution treatment,the comprehensive mechanical properties of the alloy improve.The elongation of the alloy increases significantly from 13.3%to 15.6%.