Oxidation resistance of two TiB2-based cermets

The oxidation kinetics of two TiB2 cermets containing Fe–Ni–Al-ferritic and stainless steel binder phases has been determined in air at temperatures in the range of 700–1000°C for up to 70 h. Mass gain records as a function of time and temperature showed two kinetic ranges, a parabolic one up to 775°C and a linear one above 800°C. Activation energies were observed to be 153–165 and 110–118 kJ·mol−1 for the parabolic and linear ranges, respectively. The oxidation products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results are compared to those reported for similar materials.