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

• Published in: Vacuum 2020-04, Vol.174, p.109185, Article 109185
• Main Authors: Khan, Muhammad Abubaker, Wang, Yangwei, Anjum, Muhammad Junaid, Yasin, Ghulam, Malik, Abdul, Nazeer, Faisal, Khan, Shahrukh, Ahmad, Tahir, Zhang, Hao
• Format: Article
• Language: English
• Subjects: 7055 aluminum alloy; Aging treatment; Corrosion resistance; High-temperature tensile behaviour; Spray deposited
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2020.109185

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. •Dispersion of second phase and oxide layer improved corrosion resistance of 7055-T76.•Strength of 7055 Al alloy increased due to a large volume fraction of η′ precipitates at T76.•The YS and UTS of as received 7055 Al alloy was dropped dramatically after 398 K.•7055-T76 Al alloy withstand up to 498 K and drops dramatically after 498 K.•The fracture was occurred by annihilate of dimples and agglomeration of voids.