【摘要】 利用喷射成形技术制备了Al-Zn-Mg-Cu合金。采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)等方法研究了喷射成形Al-Zn-Mg-Cu合金的沉积坯件经挤压热加工处理、固溶及时效热处理后微观组织的演变规律。结果表明,喷射成形Al-Zn-Mg-Cu合金的沉积坯件主要由大小为20～30μm的等轴晶组成,晶界第二相粗大呈不连续状分布;沉积态合金经挤压处理后,晶粒沿挤压方向拉长,晶界第二相发生碎化;挤压态合金经过固溶处理后绝大部分第二相发生回溶;峰时效处理(120℃,16h)后析出两种共格强化相,此时的强化机制是GPI区和GPII区的综合强化。更多还原

【Abstract】 In this study,the Al-Zn-Mg-Cu alloy was prepared by spray forming process.The microstructures of as-deposited,as-extruded and as-heat treated Al-Zn-Mg-Cu alloy were studied using scanning electron microscopy,transmission electron microscopy,and X-ray diffraction.The results indicate that the as-deposited alloy is composed of equiaxed grains with the average grain size of 20～30 μm and the phases on the grain boundary are in large size and in discontinuity;The grains of extruded alloy are elongated along extrusion direction and the phases on the grain boundary are cracked;After solid-solution treatment,most secondary phases in the alloy are dissolved;Two types of GP zones,GPI and GPII zones are major precipitates for the alloy under peak-aged condition.更多还原