中文摘要：

为了优化渗铝铌合金的微弧氧化工艺和了解复合涂层的抗热腐蚀性能，利用粉末包埋渗法在铌合金基体上制备渗铝层，再通过调整微弧氧化电参数以及添加剂Y（N03）3的含量获得Al2O3陶瓷膜外层，确定最佳工艺参数。以最佳工艺制备复合涂层（MAO-Y／A1／ClO3），与不含Y（N03）3制备的MAO／Al／ClO3进行对比，研究其抗热腐蚀性。结果表明：以微弧氧化膜层的硬度和厚度为主要评价指标，获得最佳参数为电压380V，频率400Hz，占空比10％，处理时间30min。添加Y（N03）3可获得均匀规则的多孔形貌；含与不含Y（NO3）3制备的试样相结构一致，都由NbAl3和γ-A1203相组成。经900℃混合熔融盐中热腐蚀50h，MAO／A1／C103和MAO-Y／A1／ClO3试样都生成A1203和NaNbO3相，其热腐蚀增重量分别为55．71mg／cm^2和45．59mg／cm^2。MAO-Y／A1／ClO3试样由于在热腐蚀阶段有更多的NaNb03生成以及微弧氧化微孔大幅减小．表现出匿优异的杭热腐件。

英文摘要：

In order to optimize the micro-arc oxidation （MAO） process of niobium alloy prepared by pack cementation aluminizing, A1203 ceramic film was obtained by micro-arc oxidation （MAO） process on aluminizing coating, and MAO electrical parameters and Y（NO3）3 additive were adjusted to get the optimum process parameters. In addition, hot corrosion resistance of the composite coating（MAO-Y/A1/C 103） prepared by the optimal process and MAO/A1/C 103 without Y（NO3）3 were comparatively investigated. Results indicate that the optimum electrical parameters are voltage 380 V, frequency 400 Hz, duty cycle 10% and processing time 30 min. Adding Y（NO3）3 into electrolyte can obtain uniform porous morphology. The specimens with and without Y（NO3）3 are both composed ofNbA13 and 李伟洲-A1203 phases. A1203 and NaNbO3 phases are formed in the MAO/A1/C103 and MAO-Y/A1/C103 with mass gains are 55.71 mg/cm^2 and 45.59 mg/cm^2, respectively, after hot corrosion at 900 % for 50 h. A lot of NaNbO3 forms and MAO micropores decreases dramatically after hot corrosion on the MAO-Y/A1/C 103 specimen, exhibiting better hot corrosion resistance.