Effects of Solid Solution Temperature on Microstructure and Mechanical Properties of 2219 Aluminum Alloy

The effects of solution treatment temperature on the microstructure and mechanical properties of 2219aluminum alloy were studied by OM, SEM, DSC and room temperature tensile test. The results show that, as the solution temperature increases from 525 ℃ to 535 ℃, the primary phases dissolve in matrix and improve the supersaturation of the matrix, which is conducive to the improvement of the mechanical properties of the alloy. When the solid solution temperature exceeds 540 ℃, over-burning occurs in the matrix, resulting in a significant decrease in the elongation. Therefore, the suitable solution treatment temperature of the alloy is 535 ℃. After the solution of 535 ℃/1.5 h and peak aging of 175 ℃/18 h, the tensile strength, yield strength and elongation of 2219 aluminum alloy are 393.5 MPa, 305.9 MPa and 8.7%, respectively.