Cycle oxidation behavior of nanostructured Ni60-TiB2 composite coating sprayed by HVOF technique

Cycle oxidation resistance at 800 °C in static air was investigated for a nanostructured Ni60-TiB2 composite coating sprayed by high velocity oxy-fuel (HVOF). For comparison, a Ni60-TiB2 conventional composite coating was also studied. The results indicate that, the oxidation processes of both composite coatings are controlled by diffusion mechanism, and the nanostructured composite coating has better cycle oxidation resistance than that of the conventional composite coating. The reasons for this improvement can be attributed to the formation of the intact SiO2 and Cr2O3 protective layer, and the enhanced adhesion between oxide film and nanostructure coating.

► Nanostructured coating has been successfully prepared by HVOF. ► We evaluate its cycle oxidation resistance at 800 °C in static air. ► The coating forms a complete-protective external oxide film during cycle oxidation. ► Nanostructured coating has excellent cycle oxidation resistance.