Influence Of Heat Treatment On The Properties Of A Ti6Al4V-10wt%WC Metal Matrix Composite Fabricated Using Selective Laser Melting

Abstract

A Ti6Al4V-10wt%WC metal matrix composite was fabricated with selective laser melting using optimal parameters of 960 mm|s laser scan speed and 200 W laser power. Cuboids and tensile test samples were printed using a continuous alternating meander scanning pattern. Ti6Al4V samples were printed for comparison purposes. Both materials were annealed to reduce brittleness which is commonly associated with the a phase in Ti6Al4V. Density, porosity, and Vickers micro-hardness were measured before and after annealing, while the microstructure was studied using x-ray diffraction, Rietveld refinement, scanning electron microscopy and energy dispersive spectroscopy. Decomposition of the WC during SLM led to the formation of TiC which increased the strength of the composite. After annealing the brittle a phase decreased while the ductile ß phase increased in both materials. The hardness and strength of the Ti6Al4V-10wt%WC was higher than Ti6Al4V after annealing, with a smaller % elongation.