The effect of Cr3C2 and TaC additives on microstructure, hardness and fracture toughness of WC-6Co tool material fabricated by Spark plasma sintering

Abstract

Spark plasma sintering has been used to successfully produce WC-6Co-xCr3C2, WC-6Co-xTaC (x = 0.2, 0.6, 1.0) and WC-6Co-xCr3C2-xTaC (x = 0.1, 0.3, 0.5) cemented carbides. The spark plasma sintered compacts were investigated by scanning electron microscopy, hardness tests and fracture toughness tests. The results were compared to an additives-free WC-6Co cemented carbide consolidated under the same process parameters and commercial ISO K10 inserts. By using Cr3C2 and TaC additives, it is possible to improve the hardness and fracture toughness of WC-Co cemented carbides. The best combination of hardness (1936 ± 15 HV30) and fracture toughness (10.38 ± 0.46 MPa·m1/2) was obtained by the WC-6Co-1Cr3C2.