Effect of low-energy laser peening on properties of NiCrBSi-WC/Co coating

Abstract

Low-energy laser peening (LE-LP) is a green and pollution-free surface deformation strengthening technology. In this work, LE-LP was used to improve the properties of NiCrBSi-WC/Co (Ni-WC) coating. The investigation focused on the impact of LE-LP on the coating microstructure, microhardness, residual stress, and tribological properties. The results showed that although laser hot melting damaged the coating surface, the phase structure of the coatings did not change significantly. The coating’s hardness increased yet its surface roughness decreased as a result of the laser peening. Concurrently, after the LE-LP treatment, a residual compressive stress with an average value of -236 MPa was tested on the surface of the coatings. The average wear volume of the coating was reduced from 11.64 × 10-2 to 6.9 × 10-2 mm3, and the average wear rate was reduced from 4.31 × 10-5 to 2.55 × 10-5/N·mm3.