关键词: 5G50铝合金, 退火温度, 组织演化, 织构, 力学性能, 表面性能, 折弯性能

Abstract: 5G50 aluminum alloy was prepared via semi-continuous casting and multi-pass rolling into sheets with a final thickness of (0.8±0.01) mm, followed by final annealing at different temperatures (100, 120, and 140 ℃) for 5 h. The effect of annealing temperature on the microstructure, mechanical properties, surface optical properties and bending performance of the sheets was systematically investigated. The results show that the grain size of the sheet slightly decreases with the increase of annealing temperature, reaching a minimum value of 15.3 μm at 140 ℃. The sheet annealed at 120 ℃ exhibits the strongest typical rolling textures (such as Brass, Copper, and Cube), indicating pronounced anisotropy, which may lead to non-uniform deformation during subsequent forming processes. Both the tensile strength and yield strength decrease with the increase of annealing temperature, while the elongation increases and reaches its peak value of 10% at 120 ℃. The sheet annealed at 120 ℃ exhibites the highest glossiness (280 GU) but a slightly lower lightness (L value) and more noticeable color shift. The surface roughness values Sa and Sz of the bend zone decreases with the increase of annealing temperature, and the best surface quality is obtained at 140 ℃.

Key words: 5G50 aluminum alloy, annealing temperature, microstructure evolution, texture, mechanical properties, surface properties, bending performance