Sintering behaviour and mechanical characterisation of Ti64/xTiN composites and bilayer components

Ceramic particle reinforcement can be used to improve the surface properties of Ti6Al4V (Ti64) alloy. Powder metallurgy route is a promising method to fabricate such reinforced Ti64 components. To assess the relevance of this technique, this work investigates the effect generated by the addition of TiN particles in Ti64 powder during free sintering. TiN reinforcement particles were randomly distributed in the Ti64 matrix with three different concentrations in two configurations: completely reinforced and unreinforced–reinforced bilayer. Dilatometry was used to obtain the shrinkage kinetics of samples at 1200, 1300 and 1400°C under inert atmosphere and to investigate the impact of reinforced particles on the sintering behaviour. The microstructure of sintered materials was shown to be lamellar in the unreinforced material and equiaxed in reinforced materials. Finally, the Vickers microhardness measurement showed the huge benefit of adding TiN particles to increase the mechanical strength of the Ti64 alloy.