Gas surface alloying of Ti6Al4V alloy by laser

The optimization of surface alloying treatments of Ti6A14V under CO2 and N-2 atmospheres with a pulsed Nd-YAG laser has been performed, trying to maximize alloyed layer hardness and minimize surface roughness. The samples were examined by light microscopy, microhardness profiles, roughness measurements and XRD. Samples obtained under a CO2 atmosphere exhibited higher hardness and lower surface roughness than those obtained under a N-2 one. Pin-on-disk wear tests were also performed to compare the wear behaviour of carburized and nitrided samples. Corrosion tests in different environments have been carried out on the nitrided surfaces in order to evaluate their behaviour in comparison to untreated surfaces.