The Effect of Anodization and Thermal Treatment on Mixed-Oxide Layer Formation on Ti–Zr Alloy

The anodization or thermal treatments applied to alloys of titanium and zirconium have a substantiated effect on the mixed-oxide layer formation compared to the naturally occurring one. A Ti–Zr 50%/50% alloy was chosen for a comparative study. Controlled, thermally treated, and anodized samples obtained with controlled procedures were analyzed in terms of morphological and compositional analysis (using SEM and EDX analysis) as well as for the determination of hardness variations. Substantial differences were observed depending on the applied functionalization method (compact of structured mixed-oxide nanotubes when the samples are subjected to the anodization procedure); there was an increase of more than six folds in the mixed-oxide layer hardness and D Shore scale, when subjected to thermal treatment, and hence, this lead to the conclusion that one may control the morphology, composition and/or the hardness of the mixed-oxide layer by applying one or another or a combination of functionalization methods.