Improvement mechanism of the oxidation resistance of Al-doped Ti(C, N)-based cermets: Influence of enriched Al in the subsurface oxide layer

The effects of Al doping on the oxidation kinetics and oxidation mechanism of Ti(C,N)-based cermets were investigated systematically. During the preparation process, Al derived from decomposed AlN powders promoted the precipitation of (Ni,Co)3Al nanoparticles in the binder phase of the cermets. The formation of (Ni,Co)(W,Mo) O4 and Co2NiO4 oxides provided essential oxidation resistance for the cermets. The presence of (Ni,Co)3Al nanoparticles was found to promote oxidation resistance by forming a continuous (Ni,Co)(Ti,Al)O3 layer within subsurface oxide layers. After 20 h of oxidation at 800 celcius, the weight gain of cermets containing 2.0 wt% AlN was only 67.49 % of that of the pure cermets.

Automated summary

The effects of Al doping on the oxidation kinetics and oxidation mechanism of Ti(C,N)-based cermets were systematically investigated. Al derived from decomposed AlN powders promoted the precipitation of (Ni,Co)3Al nanoparticles in the binder phase, and the presence of (Ni,Co)3Al nanoparticles improved oxidation resistance by forming a (Ni,Co)(Ti,Al)O3 layer.