Effect of B4C content on sintering behavior, microstructure and mechanical properties of Ti-based composites fabricated via spark plasma sintering

Abstract Monolithic titanium and composites doped with 0.24, 0.48, 0.96 and 1.92 wt% B4C were sintered by SPS method at 1200 °C for 5 min under 50 MPa. The effect of B4C as a sintering aid on sintering behavior, microstructure and mechanical properties of the composites were investigated. The maximum relative density of 99.93% was obtained for the sample doped with o.48 wt% B4C. X-ray diffraction analyses, thermodynamic assessments and microstructural investigations verified the in-situ formation of TiB whiskers and TiC particles in the composites. Moreover, the role of B4C content as a boron source was evaluated through sintering and microstructure examinations, showed the finer grain size with increasing the amount of B4C. The mechanical studies also indicated the highest microhardness value for Ti-1.92 wt% B4C composite, the best room temperature UTS/elongation results for the Ti-based sample reinforced with 0.24 wt% B4C and the highest bending strength for monolithic titanium.