Silicide coatings on Ti-6Al-1Mn (at.%) alloy and their oxidation resistance

Pack cementation was used to deposit silicide coatings on a Ti-6Al-1Mn (at.%) alloy to improve the oxidation resistance at temperatures exceeding 700 °C. The first part of this work was focused on the effect of process parameters on composition and morphology of the obtained coatings. In the second part the best silicide coatings were tested for oxidation resistance. The tests were performed in air at 700 and 800 °C in thermal cycling conditions. Morphology and composition of the silicide coatings before and after exposure were analysed by different methods including scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Significant improvement in oxidation resistance has been ascertained as a result of coating deposition.