Effect of heat treatment on the precipitate behaviour, corrosion resistance and high temperature tensile properties of 7055 aluminum alloy synthesis by novel spray deposited followed by hot extrusion

The aim of current study is to observe the microstructure characterization, corrosion resistance and tensile behaviour of spray deposited 7055 aluminum alloy. The spray deposited aluminum alloy was subjected to extrusion at 703 K and then followed by solution treatment (743 K/1.6 h) and T76 aging treatment (393 K for 6 h + 433 K for 6 h). It was revealed that large fraction of fine η′ precipitates appeared after T76 treatment. The large fraction of fine precipitates was responsible for high tensile strength, ductility and corrosion resistance. The 7055-T76 heat-treated samples yield strength and ultimate tensile strength decreased gradually up to 498 K and decreased sharply above that temperature. On the other hand, the as-received 7055 Al alloy yield strength and ultimate tensile strength decreased dramatically after 398 K. The tensile fracture was occurred at elevated temperature owing to the growth of small voids and their agglomeration.