Direct metal deposition of titanium matrix composites using B₄C powder Available to Purchase

Titanium Matrix Composites (TMC’s) containing various volume fractions of (TiB+TiC) particles were obtained by the direct metal deposition (DMD) of blends of (Ti-6Al-4V+B₄C) projected powders, through the in-situ chemical reaction 5 Ti + B₄C→4 TiB+TiC. Process optimization in terms of laser power and scanning speed allowed obtaining homogeneously distributed TiB whiskers within Titanium matrix, a full solubilisation of C for low B₄C contents (0.5 wt. % and 1.5 wt. %), and the formation of a small amount of globular TiC particles at higher B₄C content (3 %). Comparisons with Ti-6Al-4V DMD walls revealed a severe grain refinement on TMC’s due to enhanced grain germinations on TiB whiskers, even for low B₄C contents. Last, mechanical investigations indicated 10 to 15 % increases of Vickers hardness, and a constant 10 % increase of young’s modulus on a large temperature range (20-600°C) whatever the B₄C content.