Abstract:Effects of heat treatment processes on tensile properties of 2A97 Al-Li alloy were investigated. The results show that one new heat treatment process which was developed from traditional T8 temper can effectively improve the tensile properties of Al-Li alloy. In the peak-aged condition, a large quantity of fine T₁ dispersedly precipitated in the matrix. At the same time, few secondary phases precipitated at the grain boundaries, and precipitation-free zone was unobvious. The corresponding tensile strength, yield strength and elongation of alloy were 597 MPa, 549 MPa and 7.4%, respectively. In addition, BP neural network model was developed for prediction of the tensile properties of alloy subjected to different heat treatment processes. A very good correlation between experimental and predicted results was obtained, which indicates that the BP neural network can be used for the prediction of tensile properties of 2A97 Al-Li alloy.

Key words: 2A97 Al-Li alloy; heat treatment process; tensile properties; BP neural network