Oxidation Resistance of In Situ Reaction/Hot Pressing Synthesized Ti₂AlC-20% TiB₂ Composite at 600-900 C in Air

The oxidation behavior and kinetics of Ti2AlC-20vol.%TiB2 composite at 600-900 degrees C in air were investigated. The results showed that the oxidation kinetics of the composite followed a logarithmic law within the given temperature range, which indicated that the composites had excellent oxidation resistance. The selective oxidation of Al in Ti2AlC was greatly enhanced, which facilitated the formation of a continuous and dense protective layer of Al2O3. Meanwhile, the existence of molten B2O3 inhibited the outward diffusion of Ti and inward diffusion of oxygen, which prevented the growth of anatase TiO2 at 600 degrees C and rutile TiO2 at 700-900 degrees C. Therefore, the incorporation of TiB2 completely inhibited the abnormally rapid oxidation of bulk Ti2AlC at 600 degrees C and improved its oxidation resistance at 700-900 degrees C.