On the Microstructures of Spray-Deposited and Homogenized Al-Zn-Mg-Cu Alloys

In this study, a high strength Al-Zn-Mg-Cu alloy was prepared by the spray deposition technique. The microstructures of spray-deposited and homogenized Al-Zn-Mg-Cu alloys were studied using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicate that the microstructure of the spray-deposited alloy mainly is composed of the Al matrix and the Mg(ZnCu)2 compounds. The spray-deposited process has an obvious modification in size, morphology and distribution of the secondary phases in the microstructure as well as reduce of segregation. After homogenization, the coarsening of the grains in the microstructure is not obvious, a phase transformation of primary Mg(ZnCu)2 particles to Al2CuMg phase was found.