Ablation resistance of HfC coating reinforced by HfC nanowires in cyclic ablation environment

To improve the ablation resistance of carbon/carbon composites in cyclic ablation environment, SiC/HfC ceramic coating reinforced by HfC nanowires was prepared. The microstructure, bonding strength, coefficient of thermal expansion and cyclic ablation resistance of the as-prepared coating were investigated. After incorporating HfC nanowires, the bonding strength between inner SiC coating and outer HfC coating was increased. HfC nanowires could relieve the coefficient of thermal expansion mismatch between inner and outer coating and improve the toughness of the outer coating. By introducing HfC nanowires, the coated sample's cyclic ablation resistance was improved. After cyclic ablation under oxyacetylene flame for 60 s x 3, the mass and linear ablation rates of the coated sample with HfC nanowires were only 0.444 mg/s and -0.767 mu m/s, respectively. (C) 2017 Elsevier Ltd. All rights reserved.