Effect of Dissolution of η′ Precipitates on Mechanical Properties of A7075-T6 Alloy

The effects of dissolution the η′ phase by solution treatment on mechanical properties A7075-T6 alloy were investigated. Immediately after T6 sheet at 450 oC or higher, elongation significantly increased and occurred. is main hardening phase. After natural-aging, GPI, which coherent with aluminum matrix, was formed strength increased. When bake natural-aging performed, yield slightly due to partial GPI re-precipitation In contrast, 400 oC, there less increase precipitation coarse η grain boundaries low addition, when decreased insufficient nucleation site To promote reprecipitation phase, temperature set a level that would solubility. As result, through large number fine uniform effect dissolution, pre-aging introduced hardenability can be improved dissolution.