Effect of Cr2O3/Cr3C2 additions on mechanical and tribological properties of Ti(C,N)-based cermets
(1. School of Materials Science and Engineering, North Minzu University, Yinchuan 750021, China;
2. Key Laboratory of Powder Material and Advanced Ceramics, North Minzu University, Yinchuan 750021, China)
2. Key Laboratory of Powder Material and Advanced Ceramics, North Minzu University, Yinchuan 750021, China)
Abstract: Cr2O3 was used as grain inhibitor in Ti(C,N)-based cermets with vacuum sintering. The microstructure and mechanical and tribological properties of cermets with Cr2O3 and Cr3C2 were investigated. The results show that adding Cr2O3 promotes a gray core/gray rim structure formation and finer size of Ti(C,N) hard phase. Compared with the cermet with an equal Cr3C2 addition, the cermet with 0.6 wt.% Cr2O3 exhibits 16.5% higher transverse rupture strength. This enhancement is likely due to the smaller lattice misfit at the core/rim interface and more uniform Cr distribution in the binder. Additionally, at room temperature (25 °C) and 800 °C, Cr2O3-containing cermets demonstrate lower coefficients of friction and volume wear ratios than Cr3C2-containing cermets, with the wear ratio difference reaching an order of magnitude. Scanning electron microscopy and X-ray photoelectron spectroscopy results further confirm more oxidation wear in Cr2O3-containing cermets than in Cr3C2-containing cermets.
Key words: Ti(C,N); Cr2O3; grain inhibitor; mechanical properties; tribological properties