Pressure-less and current-activated pressure-assisted sintering of titanium dual matrix composites: Effect of reinforcement particle size

This paper investigates a microstructural design that can allow the tailorability of the properties of titanium–titanium boride composites. A powder processing sequence is used to allow the in situ growth of TiB whiskers in localized regions (of controlled size) of the microstructure leaving predominantly ductile titanium in between these reinforced regions. Both current-activated pressure-assisted sintering (CAPAS) and pressure-less sintering were used as high temperature consolidation processes for the powders. Superior composites in terms of consolidation, hardness and reaction completion were produced using CAPAS as opposed to pressure-less sintering. For CAPAS processed materials, the size of the reinforced regions had a significant effect on the hardness of the composites, with values ranging from 652 to 777 VHN (a 19% difference).