Experimental Research on TC4 Alloy by Laser Shock Processing

Abstract

In order to study the effect of laser shock processing (LSP) on titanium alloy, a TC4 alloy sample was processed by Nd:YAG laser with the wavelength of 1.06μm and pulse width of 12ns, and its micro-hardness and residual stress were examined and analyzed. The experimental results show that an evident strengthening layer of sample forms in the laser shock processing area. Laser shock processing improves micro-hardness and residual compressive stress of the sample significantly such as surface micro-hardness increases by up to 28.4%, the tensile stress changed into compressive stress, the layer of compressive stress distributes more than 1mm in depth and the compressive stress in the surface reaches up to -304MPa with 5J pulse energy. The effect of laser shock evidently strengthens the TC4 alloy, which improves the fatigue life of the aviation material and the performance of resist stress and rust by a large margin.