厚度对氧化铝涂层氢渗透性能的影响

Influence of thickness on hydrogen permeation properties of alumina coating

采用反应溅射法在316L不锈钢上制备了氧化铝（Al2O3）涂层。研究了涂层厚度与微观结构,以及氢渗透性能之间的关系,并对涂层的热循环性进行了评估。采用SEM分析Al2O3涂层的微观形貌,采用气相氢渗透装置对涂层氢渗透行为进行评价。结果表明Al2O3涂层的氢渗透压力指数为0.52-0.88,说明氢渗透过程机制为表面过程和体扩散过程共同控制,且体扩散过程随温度升高而增强。涂层厚度对涂层表面形貌和氢渗透性能有较大影响,涂层表面质量、阻氢性能都随涂层厚度增加先上升后降低。110nm厚的Al2O3涂层有优良的阻氢性能,热循环前后的氢渗透降低因子（PRF）分别达316和298。

Alumina coatings（Al2O3）were deposited on 316 Lstainless steel by reactive sputtering.The effect of film thickness of Al2O3 on the microstructure and hydrogen permeation property was investigated,and the thermal cycling behavior was also evaluated.The microstructure of coatings was examined by SEM,and the hydrogen permeation behavior of coatings was measured by agas-phase hydrogen permeation apparatus.The hydrogen permeation pressure exponents of the coatings are 0.52-0.88,which indicates hydrogen permeation of coating is surface and diffusion limited,and the diffusion effect is enhanced as the temperature rising.With the Al2O3 thickening,its microstructure and hydrogen permeation properties increase first and then decrease.Furthermore,Al2O3 film of 110 nm offers excellent hydrogen permeation suppression performance,with the PRF values before and after thermal cycling of 316 and 298,respectively.