Influence of residual stress on the high-temperature tribological performance of nickel-based superalloy

Abstract

This study introduces a method for generating residual compressive stress by utilizing differences in thermal expansion coefficients of materials. A corresponding experimental device has been developed. Using this method, experiments were conducted to investigate the effects of residual compressive stress on the tribological properties of the nickel-based superalloy Ni16Cr13Co4Mo. The results indicate that residual stress significantly affects the friction behavior and wear resistance of the superalloy. The stabilization time of the friction coefficient as well as the wear rate reaches a minimum under moderate residual compressive stresses. Moderate residual compressive stress can facilitate the formation of a tribo-oxide layer and enhance its bonding strength with the substrate, thereby shortening the time for stabilization of the friction coefficient and reducing the wear rate. Finite element simulation of static ball-on-disc contact model also shows that residual stress alters the internal stress distribution inside the alloy, and changes its yield and plastic behavior. Under moderate residual compressive stress, a reduction in maximum von Mises stress can be achieved, which is consistent with the variation rule of friction coefficient and wear rate in the tests.