Effect of baking time on microstructure and properties of AA7075 high strength aluminum alloy

doi:10.13251/j.issn.0254-6051.2023.11.042

Abstract

Abstract: Effect of baking time on microstructure and properties of AA7075 high strength aluminum alloy was studied by means of transmission electron microscope, universal testing machine and electrochemical testing. The results show that, with the extension of baking time, the quantity of η′ precipitates increases first and then decreases. The main phase of matrix is coarsened η phase, which is baked for 3 h. At the same time, η′ is the main strengthening phase of the alloy. The increase of η′ phases and the transformation of η′ to η promote the alloy to exhibite the trend that the strength increases first and then decreases. The alloy has the highest strength baked for 2 h, and the yield strength and ultimate tensile strength reach 392 MPa and 458 MPa, respectively. The coarse grain boundary precipitates of the specimen baked for 3 h enables the test material to reduce the grain boundary sensitivity, which hinders the corrosion propagation along the grain boundary, and improves the corrosion resistance of the alloy significantly.

Key words: AA7075 alloy, baking, microstructure, mechanical properties, corrosion resistance

CLC Number:

TG166.3

Jiang Yifu, Xu Shengnan. Effect of baking time on microstructure and properties of AA7075 high strength aluminum alloy[J]. Heat Treatment of Metals, 2023, 48(11): 254-257.

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