Microstructure, mechanical properties, and cutting performance of SPS sintered WC-CoCrFeNiB0.1 cemented carbide

High-entropy alloys (HEA) have been demonstrated as potential binder materials for sintering of WC (tungsten carbide) cemented carbide cutting tools. In the present work, WC-10CoCrFeNiB 0.1 cemented carbide samples were in-situ synthesized via a two-step low-temperature/high-temperature spark plasma sintering (SPS) process. The effects of the low sintering temperature, i.e., 700 °C, 800 °C, 900 °C, and 1000 °C, on relative density, phase composition, microstructure, and mechanical properties of the WC-10CoCrFeNiB 0.1 cemented carbide samples have been systematically investigated in this study. The results show that the high relative density of 98.5%, and the finest grain size ∼0.35 μm is obtained by the WC-10CoCrFeNiB 0.1 sample sintered with the low sintering temperature of 800 °C, which exhibits the highest Vickers' hardness of 2138 ± 22 HV, and fracture toughness of 10.37 ± 0.25 MPa·m 1/2 . The continuous cutting performance of the WC-10CoCrFeNiB 0.1 cemented carbide tool insert prepared with a low sintering temperature process at 800 °C on AISI 1045 carbon steel was observed to be improved as compared with that of the commercial WC-Co cutting insert. The results obtained in the present work can potentially provide a guideline for the preparation and the application of the high-performance HEA-bonded WC cemented carbide cutting materials.