ToF-SIMS Characterization of Nanostructured ZrO2 Coatings Applied to Near Equiatomic Ni-Ti Alloy

The ToF-SIMS technique was applied to analyze thin ZrO2 coatings deposited on the surface of a Ni-Ti alloy. Due to its nanostructured nature, these films are difficult to characterize by conventional techniques. ZrO2 coatings were deposited on near equiatomic Ni-Ti wires by pulse electrodeposition. Part of the samples was electrolytically polished before the coating process. The coated samples were then analyzed by ToF-SIMS to evaluate the influence of the deposition time and previous surface electropolishing on the structure of the deposited coating. The results indicate that thicker coatings were produced on the electropolished samples, in comparison with the as-received ones. The best uniformity in thickness was achieved when Ni-Ti samples were previously electropolished followed by ZrO2 electrodeposition for 1200 seconds. Moreover, it was possible to observe by this technique that the inclusions in the Ni-Ti matrix were not entirely covered by the coating.