Spark plasma sintering of Ti6Al4V metal matrix composites: Microstructure, mechanical and corrosion properties

Abstract

The aim of the present work is to study the synergistic effect of TiC particles (TiCp) and TiB whiskers (TiBw) reinforcement on titanium matrix composites (TMCs) fabricated by spark plasma sintering (SPS). The effect of reinforcement type and content on the microstructure and mechanical properties were investigated. Four different powder compositions were prepared by mixing TiC and B in the Ti6Al4V matrix powder. The reaction between boron and Ti resulted in in situ TiBw formation uniformly in the matrix whereas the TiC particles were accommodated at the grain boundaries. The individual contribution of both the reinforcement phases accredited to grain refinement, dispersion strengthening, and load distribution towards the final strengthening in composite was evident. An increase in both the mechanical and tribocorrosion properties was evident with TiC addition followed by a further improvement with B addition. Scanning electron microscope (SEM) and electron back-scattered diffraction (EBSD) analysis were used for confirming the grain refinement, whereas the phase determination was done using X-ray diffraction (XRD) analysis.