采用光学显微镜(OM)、透射电子显微镜(TEM)、正电子淹没谱等分析手段,研究应力、应力-电场耦合时效后2524铝合金的微观组织。研究结果表明:在190℃时效10 h时,外加130 MPa应力抑制2524铝合金中S′相的均匀形核和长大。应力(130 MPa)+电场(16 V/cm)耦合时效后,合金中出现了高密度的位错环和蜷线位错,S′相在位错和含Mn相周围细小弥散析出,晶界处PFZ缩小并出现大量细小S′相。
The optical microscope (OM), transmission electron microscope (TEM) and positron annihilation spectroscopy were used to analyze the microstructures of 2524 aluminum alloy after stress-aging and stress-electric field-aging, respectively. The results show that the homogeneous nucleation and growth of the S' phase in 2524 are restrained by the impressed 130 MPa stress after aging at 190 ℃ for 10 h. After stress (130 MPa) coupled with electric field (16 V/cm) aging, high density of dislocation loops and helical dislocations form in the alloy, fine S' phase dispersedly precipitates around the dislocations and Mn-rich phase, and the PFZ along the grain boundaries is narrowed and extensive S' phase precipitates.