Microstructure and mechanical properties and of pulse plasma compacted WC - Co

•Effect of pulse plasma compaction process, temperature, and particle size on mechanical properties of WC was studied.•Crack initiation, propagation and grain size were analyzed to discuss mechanical properties.•Quantitative measurement of porosity was carried out in reconfirming density and hardness behaviour.•Overall, microstructural characteristics were analyzed to explain hardness and fracture toughness.

Tungsten carbides-based inserts have been considered as one of the dominant hard materials in the cutting industry, receiving great interest for their excellent combination of mechanical properties. Pulse plasma compaction (PPC) process has been applied to a series of WC-Co samples with varying sintering temperature, initial particle size and sintering pressure in order to study the mechanical and microstructural behaviour. The quality of the products, as well as the mechanical properties and microstructural features this process yields, are commendable and worth looking into. A high hardness of more than 2000 HV has been achieved while a maximum fracture toughness of 15.3 MPa √ m was recorded in samples that were sintered at 1100 °C and 100 MPa. Microstructural features like grain growth and other properties are discussed with respect to the varying parameters. While grain size shows an incremental pattern with increasing temperature, it was still possible to limit them to a great extent ensuring high mechanical properties. The effect of sintering pressure in the range of 60–100 MPa, while keeping sintering temperature constant, was found to be almost negligible.