Microstructure and tribological performance of novel Ni-based alloy cladding with excellent high temperature wear resistance and self-lubrication performance

Abstract

This paper aims to study the laser cladding of Ni-based alloy coatings with excellent high temperature wear resistance and self-lubrication performance on the surface of parts such that meet complex metallurgical service conditions. The composite alloy powders were formed by adding 3 wt%–11 wt% WS2 and Ti powder to NiCrCoMoBSi alloy powder, and the novel Ni-based alloy samples with high temperature wear resistance and self-lubrication performance were cladded on the surface of Cr28Ni48W5 substrate by laser cladding. The results show that the addition of WS2 and Ti powder had a significant influence on the microstructure evolution and high temperature wear resistance and self-lubrication performance of the samples. The laser cladding coating with 7 wt% WS2 and Ti had the 3 % TiS self-lubricating phase and 19 % enhanced phase with the best microstructure matching relationship, which improved the high temperature wear resistance and self-lubrication performance of the sample. At 800 °C, compared with the Cr28Ni48W5 superalloy substrate, the friction coefficient of the laser cladding coating was 0.22 and the wear ratio was 1.70 × 10−5 mm3 N−1 m−1, which were reduced by 60 % and 54.67 % respectively. The mechanism of the enhanced wear resistance and self-lubrication performance was elaborated.