固溶处理对喷射成形1420铝锂合金组织和性能的影响

对喷射成形挤压态的1420铝锂合金进行不同温度、不同时间的固溶处理。采用光学显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电子万能试验机对合金的显微组织和力学性能进行分析。结果表明:挤压态合金中分布着大量Al₃Li、AlLi粒子。经450 ℃×0.5 h固溶处理后可获得细小的组织和良好的综合力学性能;第二相颗粒基本溶入合金基体中,抗拉强度为377.47 MPa,伸长率为17.3%,晶粒平均尺寸为2.91 μm;合金的断裂方式为韧性断裂。随着固溶温度、时间的增加,裂纹起源于合金缺陷处,以穿晶的方式扩展。

Effect of solution treatment on microstructure and properties of spray formed 1420 Al-Li alloy

Extruded spray formed 1420 Al-Li alloy was solution treated at different temperatures for different time. The microstructure and mechanical properties of the alloy were analyzed by optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and electronic universal testing machine. The results show that a large number of Al₃Li and AlLi particles are distributed in the extruded alloy. After solid solution treatment at 450 ℃ for 0.5 h, the alloy can obtain fine microstructure and good comprehensive mechanical properties, with the average grain size being 2.91 μm, the second phase particles dissolved into the matrix, the tensile strength and the elongation being 377.47 MPa and 17.3% respectively, and the fracture mode of the alloy is ductile type. With the increase of solution treatment temperature and time, the cracks originate from the defects and propagate in transgranular mode.