Fabrication and evaluation of high-entropy alloy reinforced Fe bond diamond tool

Abstract

Metal-bond diamond tools find extensive use in the grinding of hard and brittle materials. The mechanical properties and wear resistance of the metal bond are crucial for the grinding performance and life of diamond tools. However, Fe bonds exhibit insufficient hardness, strength, and wear resistance, and existing reinforcement methods are difficult to simultaneously improve the self-sharpness and wear resistance of diamond tools, leading to a trade-off between grinding performance and life. In this paper, a novel AlCoCrFeNi HEA particles reinforced Fe (HEA/Fe) alloy was proposed as the bond for diamond tool to address the aforementioned issue. The work considers materials science fundamentals related to the element diffusion mechanism and particle reinforcement mechanism in the design of the HEA/Fe bond. Through the mutual element diffusion between the HEA and Fe matrix, expanded HEA regions are formed, which not only enhance the strength and overall wear resistance of the HEA/Fe bond but also generate a composite structure with varying hardness. The distinct mechanical properties of composite structure form wear-resistant and non-wear-resistant areas within the diamond tool, effectively balancing the challenging trade-off between wear resistance and self-sharpness. This allows HEA/Fe bond diamond tools to achieve both prolonged service life and high grinding performance. The results reveal that the HEA/Fe bond diamond tool exhibits a lower grinding force, a superior surface finish, and a nearly equivalent grinding ratio compared to the commercial Fe-based alloy bond diamond tool in grinding of sapphire.