Unraveling the Friction and Wear Characteristics of the High Hardness, Low Young's Modulus 60NiTi Alloy: A Synergistic FEM Simulation and Experimental Study

Abstract

A finite element model of 60NiTi plate and Si3N4 ball (wear system) was established based on the discrete modified Archard model. The CSS-42L bearing steel with high Young's modulus was chosen as contrast material. The stress distribution, depth of wear marks, and wear rate were quantitatively analyzed to evaluate the feasibility of low Young's modulus of 60NiTi as bearing material. The FEM results revealed that the subsurface stress distribution exhibited a trend of first rising and then falling along the depth direction, and the peak stress position of 60NiTi alloy was found at about 100µm from the surface under a 30N load. The peak stress was reduced by 22.7% compared with the CSS-42L bearing steel at a 30N load, which demonstrating the superior load resistance of 60NiTi alloy. After undergoing friction and wear, the surface hardness of 60NiTi alloy was higher than the original hardness. Additionally, a significant increase in subsurface hardness was also observed due to same processes. Furthermore, the distribution and peak position of hardness along the depth direction was similar to the stress obtained from FEM, which indirectly confirmed the reliability of FEM simulation.