Enhanced mechanical properties and high temperature oxidation resistance of Ti(C,N)-based cermets containing Zr.

Abstract (Ti 1-x ,Zr x)(C 0.5 ,N 0.5)-Co cermets doped with various zirconium (x = 0, 0.05, 0.1, 0.15) were fabricated by in-situ carbothermal reduction-nitridation and liquid phase sintering-HIP treatment at 1500 °C. The microstructure, mechanical properties and oxidation resistance of (Ti 1-x ,Zr x)(C 0.5 ,N 0.5)-Co cermets were characterized by scanning electron microscope, X-ray diffraction, mechanical properties tests and high temperature oxidation experiment. The results showed that the existence of zirconium in cermets could refine the hard phase grain and improve the mechanical properties of cermets. The proper zirconium addition promoted the formation of a dense protective layer on the surface of cermets at the high temperature, which might reduce the diffusion rate of the oxygen atom and enhance the oxidation resistance of cermets. Highlights • The (Ti,Zr)(C,N)-Co cermets with the different Zr additions were fabricated. • The addition of extra Zr can inhibit the growth of hard phase particles in the sintering process. • The addition of extra Zr can enhance mechanical properties and oxidation resistance obviously. • The Zr-doped cermets hold great potential in machining and structural applications. [ABSTRACT FROM AUTHOR]