激光冲击强化对激光增材TC4钛合金组织和抗氧化性的影响

In recent years, laser additive manufacturing(also called 3D printing) has become the focus of scientific research and industrial applications. In order to study the impact of laser shock peening(LSP) on the properties of laser additive manufactured Ti-6Al-4V alloy, a TC4 titanium alloy prepared by 3D printing was carried out LSP by using Nd:YAG laser with energy of 5 J, wavelength of 1 064 nm, pulse width of 10 ns and spot diameter of 3 mm, and the micro-hardness, microstructure, residual stress and high temperature oxidation performance of the material before and after LSP were analyzed. The results show that by comparing with the TC4 titanium alloy before LSP, the micro-hardness of that after LSP increases by 8%, and the depth of the impact layer reaches 0.4 mm, the grains in the strengthened region are refined, the dislocation is increased and the deformation twins are produced. The residual compressive stress of laser shock peening is as high as 472 MPa, and the high temperature oxidation resistance of the material is also improved.