Heat Treatment Process of 2A50 Aluminum Alloy Prepared by Laser Melting Deposition Method

In order to improve the comprehensive mechanical properties of additive components, the heat treatment process of high strength wrought 2A50 aluminum alloy was studied based on the laser melting deposition technology. The effects of different heat treatment parameters on the microstructure and mechanical properties of additive samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness tester and tensile test. The results show that the as deposited samples have obvious columnar dendrite structure. After heat treatment, the coarse columnar dendrites fracture, and the grains begin to spheroidize and form a uniformly distributed massive second phase at the grain boundary. Under the optimized heat treatment conditions (540 degrees C/1 h+150 degrees C/16 h), combined with the solid solution strengthening of solute elements and the precipitation strengthening of the second phase, the average values of yield strength, tensile strength and microhardness (HV) of the additive samples increase from 85, 207 and 889.55 MPa in the as deposited state to 245, 321 and 1344.56 MPa after heat treatment, respectively.