Effect of B₄C Size on Tensile Property of (TiB+TiC) Particulate Reinforced Titanium Matrix Composites by Investment Casting

Abstract

The aim of this research is to evaluate the microstructure and tensile property of in-situ particulate (TiB+TiC) reinforced titanium matrix composites (TMCs) synthesized by investment casting process. Different size of B₄C (1500, 150 and 0.5 μm) were added to the titanium matrix during vacuum induction melting which can provide the in-situ reaction of 5Ti+B₄C=4TiB+TiC. The tensile property of TMCs was investigated in accordance with the reinforcement distribution by B₄C size. The size and morphology of in-situ reinforcements were quite different according to the B₄C size. In-situ synthesized reinforcements by fine B₄C were very minute and distributed homogeneously than coarse B₄C. Moreover, the improvement of the tensile strength and ductility of TMCs was caused by not only load transfer strengthening but also the matrix grain refinement and homogeneous distribution of the reinforcements.