【摘 要】
：
Chemical vapor deposition (CVD) zirconium carbide (ZrC) coating can improve the oxidation and ablation resistance of thermal structure component materials such as C/C and C/SiC composites [1].Generall
【机 构】
：
Institute of Powder Metallurgy, Institute for Advanced Materials and Technology, University of Scien
【出 处】
：
2016’中国溶胶-凝胶学术研讨会暨国际论坛
论文部分内容阅读
Chemical vapor deposition (CVD) zirconium carbide (ZrC) coating can improve the oxidation and ablation resistance of thermal structure component materials such as C/C and C/SiC composites [1].Generally,transmission and strict control of Zr-source precursor is the most critical technology in CVD ZrC process [2, 3].A bromination apparatus was designed and manufactured to accurately control the flow rate of ZrBr4 vapor.Zirconium carbide (ZrC) coatings were deposited on graphite substrate at 1250℃ by low pressure chemical vapor deposition (LPCVD) with Br2-Zr-C3H6-H2-Ar system.The effects of gas composition (input Zr/C ratio) on the morphology and growth mechanism of ZrC coatings were investigated.The coating deposition process was controlled by surface reaction kinetics at the input Zr/C ratio of 0.5, leading to a loose structure.When the input Zr/C ratios were 1 and 1.5, coating growth was dominated by diffusion kinetics, resulting in (200) preferential orientation with a dense column structure.Meanwhile, ZrC coating without free carbon was produced at the input Zr/C ratio of 1.5.
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