Dry grinding of hard and brittle materials has received increasing attention due to the environmental issues associated with using coolants and the need for machine tooling under dry conditions. However, during dry grinding, the high grinding temperature may induce thermal deformation of traditional metal bonds and accelerate the wear of diamond tools. In the present study, a refractory high-entropy alloy (RHEA) was introduced into Fe alloy to serve as the metal bond of diamond tool in order to improve the dry grinding performance. First, RHEA powders (composed of WMoTaNbV) were prepared by discharge plasma ball milling (DPBM) as well as planetary milling (PM) for comparison. The effect of ball milling time on the microstructure of RHEA powder was examined. Then, RHEA/Fe alloy was prepared by hot-press sintering, and the microstructures, mechanical properties and wear resistance of sintered RHEA/Fe alloys with different contents of RHEA were investigated. Finally, a RHEA/Fe alloy bond diamond tool was prepared to evaluate the dry grinding performance on a silicon nitride ceramic. The results indicated that RHEA powder was successfully synthesized by DPBM milling for only 15 h, which was a much shorter duration compared to PM method. With increasing RHEA content in the range of 0-20 wt%, the relative density of RHEA/Fe alloys decreased, but the hardness, compressive strength, and wear resistance increased. Good bonding was achieved between 20wt.%RHEA/Fe alloy and diamond grits in the synthesized diamond tool at the sintering temperature of 1050 °C. During dry grinding of silicon nitride ceramic, the diamond tool based on 20wt.%RHEA/Fe bond exhibited a lower grinding force, higher grinding ratio, and reduced wear in comparison with commercial Fe alloy bond diamond tool, showing excellent potential for the dry grinding of ceramics.
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