Characterization of Ti6Al4V–Ti6Al4V/30Ta Bilayer Components Processed by Powder Metallurgy for Biomedical Applications

The design and fabrication of a bilayer Ti6Al4V–Ti6Al4V/30Ta component were performed by using the powder metallurgy process and solid-state sintering as the consolidation step. Phase change and sintering densification of the component were studied by dilatometry. The addition of 30 vol% of Ta to the Ti6Al4V matrix had a noticeable effect over the microstructural and mechanical properties of the alloy, which showed decrements of up to 12.2 and 21.5% in nano-hardness and elastic modulus, respectively. The decrement of these properties strongly affected the wear and corrosion performance of the component. Special attention was focused on the intermediate zone between layers denoted by a transition zone, which presented better wear response because of the properties and microstructure caused by the gradient diffusion of Ta. Ti6Al4V/30Ta alloy showed an improved corrosion behaviour compared to Ti6Al4V alloy, decreasing 2.4 times their susceptibility to corrosion and about two orders of magnitude their corrosion rate. The bilayer component in this study is proposed as an alternative to decrease the consumption of expensive materials with improved properties.