Effect of Ni Content on the Reaction Behaviour and Microstructure of TiB_2- TiC/Ni Cermets Synthesized by MASHS

In this paper TiB_2-TiC/Ni cermets with various Ni (20, 40 and 60 wt %) contents were synthesized by mechanically activated self-propagating high-temperature synthesis (MASHS) and the effects of the addition of Ni were investigated on synthesis parameters and microstructure of the synthesized samples. Raw materials (B_4C, Ti and Ni) were first milled in Ar atmosphere. Powders were then synthesized in the tube furnace. The samples were analyzed by XRD and SEM. Ignition time of the samples was decreased by increasing Ni content. The SEM images show that the microstructure of samples has been fined and the pore size has been decreased by increasing Ni content. The crystallite size of synthesized samples has been calculated by Rietveld method. The average crystallite size of TiB_2 and TiC phase in the sample with 60 wt % Nickel was 53 nm and 22 nm, respectively.