(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究时效时加高强电场对2E12铝合金的力学性能和微观组织的影响，采用力学性能测试及透射电镜检测材料的力学性能和微观组织，并分析电场对2E12铝合金的作用机理。结果表明：16 kV/cm电场时效使晶内S′相(Al2CuMg)粒子变得更加细小，电场也使T相(Al20Cu2Mn3)粒子变小，这略微降低了2E12铝合金的屈服强度；加电场时效时，合金晶界上析出相细小弥散使合金的塑性提高；电场一方面能够促进S′相的形核，另一方面也能抑制其长大和粗化；空位扩散时，电场影响了空位周边的势场，使空位倾向于朝电场强度的反方向运动。
关键字: 2E12铝合金；电场；时效；力学性能；微观结构
microstructures of 2E12 aluminum alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The influence of electric field aging on the mechanical properties and microstructures of 2E12 aluminum alloy was investigated by means of mechanical tests and transmission electron microscopy (TEM). The mechanism of the effect of an electric field was analyzed. The results show that the S′ phase(Al2CuMg) particles and T phase(Al20Cu2Mn3) particles are smaller after 16 kV/cm electric field aging, which decreases the yield strength of the alloy. Meanwhile, the grain boundaries of the specimen aged in electric field are composed by numerous ultra micro precipitates, and the ductility of the alloy is improved. The electric field can accelerate the nucleation of the new phase S′, while the coarsening of the S′ phase is retarded by the electric field during the aging process. The electric field can influence the potential field of vacancies. As a result, the vacancies tend to move toward the opposite direction of the electric field.
Key words: 2E12 aluminum alloy; electric field; aging; mechanical properties; microstructure
