Investigation of microstructure and tribological property of Ti-6Al-4V alloy by laser shock peening processing

Abstract

Laser shock peening (LSP) is a process to introduce compressive residual stresses for improved surface properties of materials. In this study, the effect of LSP on the microstructure and tribological property of Ti-6Al-4V alloy was investigated. The surface and cross-sectional microstructure of the samples show that the shape of the β phase changes from a long strip to a short bar and granular after the LSP treatment. With the increase of laser energy, the surface roughness decreases gradually while the surface microhardness is increased. The maximum hardness is on the surface, and with the increase of the depth, the hardness decreases until a stable value of 339.4 HV which is the microhardness of the matrix. The thickness of the high-microhardness layer is about 350 μm. LSP treatment can decrease the average friction coe cient and effectively improve the tribological property of Ti-6Al-4V alloy. The higher the laser energy, the better the wear resistance. This study is helpful for further study and applications of the LSP process in improving the tribological property of Ti alloys. Recently, research has been performed in the eld of LSP, mainly focusing on common metal materials such as steel [22], aluminum alloy [23], and titanium alloy [24]. Bai et al. [25] studied the improvement of

Possibility of Phase Transformation of Al2O3 by a Laser: A Review

“…Laser shock peening (LSP) is an advanced surface treatment technique based on laser shock-induced plastic deformation without a thermal effect. These shockwaves induce changes in the material microstructure and residual stress distribution, resulting in improved surface hardening, wear resistance, and tribological performance [79,80]. Shukla et al [81] demonstrated increased net compressive stresses from 104 MPa to 168 MPa using LSP on Al 2 O 3 ceramics.…”