Effect of laser shock processing on mechanical properties of Ti-45.5Al-2Cr-2Nb-0.15B alloy

Abstract In order to study the effect of laser shock processing (LSP) on mechanical properties of Ti-45.5Al-2Cr-2Nb-0.15B alloy. The Ti-45.5Al-2Cr-2Nb-0.15B alloy samples, after the treatment of vibration stress relief, were LSP treated by a high energy nanosecond Nd:YAG laser. The surface micro-hardness, surface residual stress and surface roughness of samples prior & after the LSP treatment were tested by the micro-hardness tester, hole-drilling strain method and the roughness tester, respectively. The experiment results show that after the treatment of LSP, resulting in a certain residual compressive stress on the surface of the sample. When the laser energy is increased to 7 J, the surface residual stress is increased from 0 MPa to -311 MPa, the surface micro-hardness is increased from 311 HV to 366 HV, and the surface roughness is increased from 43 μm to 72 μm. With the treatment of LSP, the mechanical properties of Ti-45.5Al-2Cr-2Nb-0.15B alloy is improved greatly.