Ablation behavior of SiC/ZrB2 ultra-high temperature ceramic coatings by solid shielding shrouded plasma spray for high-temperature applications (temperature above 2000 °C)

In this paper, ablation behavior of C/SiC/ZrB2 ultra-high temperature ceramic coatings applied by solid shielding shrouded plasma spray method was studied for as nose tip, leading edges, solid-fueled rocket nozzles, propulsion systems, re-entry missile nozzles throat applications. For this purpose, SiC inner layer coating was applied by reactive melt infiltration (RMI) under argon atmosphere. Then, ZrB2 outer layer coating was deposited on SiC coated graphite by solid shielding shrouded plasma spraying (SSPS). To evaluate the performance of the coating, SiC and SiC/ZrB2 coatings were exposed to oxy-propane and oxy-acetylene flames at 90 degrees angle. The results of ablation test showed that mass ablation rates of SiC/ZrB2 coating under oxy-propane flame after 300 s and under oxy-acetylene flame after 120 s is 0.426 x 10(-4) g.cm(-2).s(-1) and 4.8 x 10(-4) g.cm(-2).s(-1) respectively. It seems that ablation behavior of SiC/ZrB2 coatings are controlled by the formation of the ZrO2 dense layer.