Abstract: Effect of extrusion temperature on the microstructure and properties of the Al-Cu-Mg alloy 2A12 was studied by means of scanning electron microscopy (SEM), universal testing machine and Vickers hardness tester. The results show that after hot extrusion between 380-470 ℃, the primary second phase in the 2A12 alloy microstructure is crushed into island-like second phase, strip-like phase distributing along the extrusion direction, and small particle-like second phase is dispersed. With the increase of extrusion temperature, the granular second phase decreases gradually, the strength and hardness of the alloy increase gradually, but the elongation decreases gradually. The tensile strength, yield strength and hardness of the 2A12 alloy extruded at 470 ℃ are increased by 61.7%, 63.2% and 54.1%, respectively, which is higher than the homogenized 2A12 alloy.

Key words: 2A12 alloy, extrusion temperature, microstructure, properties