Ablation resistance property of TiC/ZrO2 coating deposited by plasma-spraying

Abstract:

In high temperature ablation process, the TiC coating will be oxidized to TiO₂. The thickness of molten TiO₂ increases when the temperature is higher than 2000℃, which decreases the bonding strength of coating. In this study, the TiC/ZrO₂ coatings with different content of high melting phase ZrO₂ were deposited by plasma spraying, in order to improve the anti-scouring property of TiC coatings. The phase structure, microstructure and composition of coatings, before and after ablation, were characterized by XRD, SEM and EDS, respectively. The ablation resistant mechanism of coatings with high melting phase ZrO₂ was discussed. The results indicate that the TiC/ZrO₂ coating shows good ability of ablation resistance, and its weight loss is only 1.5×10_-4 g.cm_-2.s_-1 at 2000℃. The ZrO₂ layer formed during the ablation can restrain the further oxidation of inner TiC and reduce the shearing force of oxyacetylene flame, which improves the anti-scouring property of coatings.