(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 采用等离子喷涂技术成功在坯体密度为1.8 g/cm3 炭/炭复合材料上面制备厚度为1.2 mm与基体结合良好的较致密的W涂层的试样。利用氧乙炔焰分别测试其在30 s、60 s、90 s和120 s下的烧蚀性能。结果表明:试样的质量烧蚀率和线烧蚀率均随时间的增加而增加。其中，最大质量烧蚀率和线烧蚀率分别为7.8 μg/s和3.5 μm/s。XRD、SEM分析表明:在烧蚀中心区，涂层试样的烧蚀以升华分解为主，同时，还伴有氧化烧蚀和微区机械剥蚀；在烧蚀过渡区，涂层的烧蚀机制以热氧化和燃气冲刷为主；而在烧蚀边缘区，涂层的烧蚀则主要表现为弱氧化烧蚀。
关键字: 大气等离子喷涂；耐烧蚀；W涂层；炭/炭复合材料
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Compact tungsten coatings with thickness of 1.2 mm were successfully deposited by the atmosphere plasma spraying technique on carbon/carbon composites with the density of about 1.8 g/cm3. W coating ablation resistances were studied by using oxyacetylene flame for 30 s, 60 s, 90 s and 120 s. The results show that both the mass ablation rate and linear ablation rate increase with the ablation time prolonging. The maximum mass ablation rate and linear ablation rate are 7.8 μg/s and 3.5 μm/s, respectively. The phase compositions and microstructures of the composites before and after ablation were examined by XRD and SEM. In the ablation center, the ablation mechanism of the coated sample is sublimation and decomposition, combined with thermo-oxidation and mechanical denudation. In the transitional field, the ablation mechanism of the coating is controlled by thermo-oxidation and scouring. And in the ablation rim, the coating exhibits slight oxidation behavior.
Key words: air plasma spray; ablation resistance; W coating; carbon/carbon composite
