분무 Al-Zn-Mg 합금의 기계적 성질 및 미세조직에 미치는 Ag 첨가의 영향

Abstract

The overall objective of this study is to investigate the effect of Ag addition on the mechanical properties and microstructure of rapid solidified 7000 Al series alloys. Al-Zn-Mg-Cu alloys with small amounts of Ag was fabricated into the powder by gas atomization. The powder was extruded after the cold compaction and degassing and then followed by T6 heat treatment. Microstructure observation, phase analysis, room and high temperature tensile test and hardness test were pursued. The tensile strength and hardness of Ag-added alloy after heat treatment was increased with increasing Ag contents. However, the elongation of extruded alloys was not increased as much as to be expected. The reason of this result seems to be related to theΩ phase, which contribute to the high temperature strength stability of Al-Cu-Zn alloys through the formation of eutectoid with Ag addition. (Received September 13, 1999)