Preparation of fine-grained WC-4Co cemented carbides cutting tools with engineered surface micro-features by SPS and performance analysis

Abstract

WC-Co cemented carbides, renowned for their excellent wear resistance and impact toughness, are considered ideal materials for cutting tools. A novel rapid preparation method based on spark plasma sintering (SPS) is introduced to efficiently produce fine-grained cemented carbide cutting tools with engineered surface micro-features. The effects of compaction parameters (compaction pressure, holding time) and sintering parameters (sintering temperature, dwell time) on the microstructure, mechanical properties, and shape retention were systematically investigated in WC-4Co fine-grained cemented carbides. The results demonstrate that compaction at 3.0 × 10³ kg with a 60-min holding time optimized green density (53.67 %) and shape fidelity (>90 %), thereby preventing crack formation induced by high pressure and extended duration. Sintering at 1350 °C for 10 min yielded optimal overall properties (hardness: 19.12 GPa; fracture toughness: 8.47 MPa·m^1/2) while effectively suppressing abnormal WC grain growth. The η phase (Co₃W₃C) was found to accumulate exclusively on the surface and could be effectively eliminated through polishing. Turning experiments show that the main cutting force, feed force, passive force and cutting temperature of micro texture tools are reduced by 4.95–14.58 %, 13.35–26.72 %, 7.65–27.25 % and 4.21–9.82 % respectively compared with non-texture tools. The micro-texture on the front cutting surface also effectively prevents the formation of chip accumulation. This research provides both a theoretical foundation and technical support for the efficient production of high-performance micro-textured cutting tools.