Fabrication of Multi-Layered Ti-Ta-Zr Coatings by Non-Vacuum Electron Beam Cladding

In this study Ti-Ta-Zr coatings fabricated on VT1-0 titanium substrates by non-vacuum electron beam cladding in one, two and three passes were investigated. Coatings were characterized by a high quality; such defects as cracks and voids were not observed. The structure of coating was commonly dendritic. The acicular structure in the one-layered coating and in the first layer of multilayered coatings was revealed by using scanning electron microscopy (SEM). The results of the energy dispersive X-ray (EDX) analysis indicated the presence of tantalum and zirconium segregations in dendrite arms and in the space between them. It was found that dendritic branches contained the maximum of tantalum while an increased amount of zirconium was concentrated in the interdendritic space. The maximum concentration of alloying elements (56.87 wt. % Ta and 22.22 wt. % Zr) was obtained in the layer cladded in the third pass of an electron beam. The microhardness of Ti-Ta-Zr layers rose from 4.5 GPa to 6 GPa with an increase in .the percentage of alloying elements