In-situ synthesis of multi-element cemented carbides using the “trinity” method

Ultrafine/nano cemented carbdes have broad application prospects due to their excellent properties such as high strength and high hardness. However, there are many challenges in obtaining alloys with high hardness, strength and toughness. Multi-element alloys were prepared by a “trinity” technology using spark plasma sintering (SPS) in-situ synthesis with nano WO₃, Co₃O₄, Cr₂O₃, V₂O₅, nano-carbon black as raw materials and multi-walled carbon nanotubes (MWCNTs) as reinforcing materials. The results indicate that specimens prepared at 1340 °C, 30 min and 50 MPa have more uniform microstructure and higher mechanical properties. The Vickers hardness and fracture toughness of the sample are 23.50 GPa and 13.15 MPa•m^1/2, respectively. During the in-situ preparation process of SPS, oxides are transformed into carbides and elemental Co while achieving densification.