Effect of particles size of TiC on oxidation resistance of in-situ TiC/ Ni composite

The oxidation resistance of TiC/Ni composites is crucial for its application in high-temperature oxidation environment. The in-situ TiC/Ni composites are fabricated by reactive sintering method, and the influence of TiC particle size on oxidation resistance of composite is studied. The particle size of TiC increases from 1.54 & mu;m to 2.40 & mu;m as the sintering holding time prolongs from 2 h to 6 h, due to the dissolution-reprecipitation mechanism. The oxidation kinetics of in-situ TiC/ Ni composite with different TiC particle size oxidized at 800 degrees C for 100 h obeys parabolic kinetics. The oxidation mass gain of composite increases from 7.471 mg & BULL;cm  2 to 8.454 mg & BULL;cm  2, and the oxide scale on composites becomes thicker, as the particle size of TiC increases from 1.54 & mu;m to 2.40 & mu;m. The reduction of TiC particle size facilitates the formation of a dense and continuous oxide scale on composite, helpful to restrict the diffusion of O, Ti and Ni atoms during oxidation. Therefore, the reduction of TiC particle size is contributed to the optimization of oxidation resistance of in-situ TiC/Ni composites.