In situ preparation of (TiB + TiC + Nd2O3)/Ti composites by powder metallurgy

Titanium matrix composites reinforced with multiple ceramic particulates TiB, TiC and Nd2O3 were prepared by powder metallurgy utilizing the chemical reactions among Ti, B4C, NdB6 and oxygen in Ti powder. The thermodynamic feasibility of the in situ reaction has been calculated. The phases were identified by X-ray diffraction (XRD). The result shows that multiple ceramic phases TiB, TiC and Nd2O3 particulates have been synthesized. The microstructures were examined by means of optical microscopy (OM), scanning electron microscopy (SEM), backscattered electron microscopy and transmission electron microscope (TEM). The results show that the reinforcements are distributed uniformly in the matrix alloy and grow in different shapes. TiB grows in needle shape; TiC and Nd2O3 grow in equiaxed or near-equiaxed shapes. The addition of NdB6 is beneficial to grain refinement, grain-boundary purification and porosity reduction.