Producing Ti5Mo-Fused Tracks and Layers via Laser Powder Bed Fusion

Abstract

The principal optimum process parameters for printing Ti5Mo fused tracks and layers were determined. The laser power, scanning speed and hatch distance were varied to study their influence on fused track and layer formation. The morphology, geometry, homogeneity, surface roughness, solidification structure, microstructure and microhardness of the fused tracks and layers were analysed. It was observed that, based on the laser energy density, different fused tracks and layers can be achieved. It is only at a certain critical threshold that optimum process parameters could be obtained. Laser power of 200 W with a corresponding scanning speed of 1.0 m/s at a hatch distance of 80 µm was obtained as the optimum process parameter set. As opposed to previous research by the authors, the Mo powder particles in the current investigation melted completely in the Ti5Mo alloy matrix due to the small Mo powder particle size (1 µm). A 50% offset rescanning strategy also improved the surface quality of the layers. The solidification front is predominantly cellular, and the microhardness values obtained fall within the values reported in the current literature.