α/γ相比率调控对超音速等离子喷涂Al2O3阻氚涂层微结构及性能的影响

采用超音速等离子喷涂技术在中国低活化马氏体钢表面制备不同α/γ相比率的Al₂O₃阻氚涂层，研究了α/γ相比率调控对Al₂O₃涂层微观结构、力学性能和耐电化学腐蚀性能的影响。利用掠入射X射线衍射（GIXRD）和扫描电子显微镜（SEM）表征Al₂O₃涂层的微观结构、粘结拉伸试验法和纳米压痕仪表征涂层的力学性能、动电位极化曲线法测试涂层的耐电化学腐蚀性能。研究结果显示：通过调控特征喷涂参数（CPSP），Al₂O₃涂层中α相含量从78.6%至24.4%可控调节，且孔隙率从2.8%降低至1.5%；α相含量为78.6%的Al₂O₃涂层硬度为(11.500±0.575) GPa，约为高γ相含量(75.6%)涂层的2倍；且高α相含量(78.6%)涂层的腐蚀电流密度较高γ相含量(75.6%)涂层的腐蚀电流密度低1个数量级。以上结果表明，高α相含量(78.6%)的Al₂O₃涂层具有更优异的力学性能、耐电化学腐蚀性能以及耐Cl^-扩散穿透能力，具有应用于聚变堆结构材料表面阻氚涂层的潜能。

Microstructure and Property of Al2O3 Tritium Resistance Coating with Different Ratios of α/γ Phase Sprayed by Supersonic Atmospheric Plasma Spraying

Al₂O₃ tritium resistance coatings with different ratios of α/γ phase were sprayed on China-low activation martensitic steels by supersonic atmospheric plasma spraying technology. The effects of ratio of α/γ phase on microstructures and properties of Al₂O₃ coatings were investigated. GIXRD and SEM were carried out to characterize the microstructures of the Al₂O₃ coatings, tensile test and nano-indentation test were performed to measure mechanical properties of the Al₂O₃ coating, and the potentiodynamic polarization method was performed to test the property of corrosion resistance. The results show that the content of α phase in the Al₂O₃ coating is controlled from 78.6% to 24.4% by adjusting the critical plasma spray parameters (CPSP). And the porosity of the Al₂O₃ coatings decreases from 2.8% to 1.5%. The hardness is (11.500±0.575) GPa of the sample with α phase content of 78.6%, which is about twice the hardness of the coating with γ phase content of 75.6%. Compared with the Al₂O₃ coating with γ phase content of 75.6%, the corrosion current density of Al₂O₃ coating with α phase content of 78.6% decreases by one order of magnitude. The above results indicate that the Al₂O₃ coating with high α phase content of 78.6% displays better mechanical properties, electrochemical corrosion resistance and Cl^- diffusion penetration resistance, and possesses potential application in the tritium resistance coatings on the surface of structural materials of fusion reactor.