渗铝铌合金的微弧氧化及热腐蚀性能
发布时间：2019-08-24 11:37
【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(NO_3)_3的含量获得Al_2O_3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/Al/C103),与不含Y(NO_3)_3制备的MAO/Al/C103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380 V,频率400 Hz,占空比10%,处理时间30 min。添加Y(NO_3)_3可获得均匀规则的多孔形貌;含与不含Y(NO_3)_3制备的试样相结构一致,都由NbAl_3和γ-Al_2O_3相组成。经900℃混合熔融盐中热腐蚀50 h,MAO/Al/C103和MAO-Y/Al/C103试样都生成Al_2O_3和NaNbO_3相,其热腐蚀增重量分别为55.71 mg/cm~2和45.59 mg/cm~2。MAO-Y/Al/C103试样由于在热腐蚀阶段有更多的NaNbO_3生成以及微弧氧化微孔大幅减小,表现出更优异的抗热腐性。
[Abstract]:In order to optimize the micro-arc oxidation process of aluminized niobium alloy and understand the thermal corrosion resistance of the composite coating, the aluminizing layer was prepared on the niobium alloy substrate by powder embedding infiltration method, and then the outer layer of Al_2O_3 ceramic film was obtained by adjusting the electric parameters of micro-arc oxidation and the content of additive Y (NO_3) _ 3, and the optimum technological parameters were determined. The thermal corrosion resistance of composite coating (MAO-Y/Al/C103) prepared by the best process was compared with that of MAO/Al/C103 prepared without Y (NO_3) _ 3. The results show that the hardness and thickness of the micro-arc oxide film are taken as the main evaluation indexes. The optimum parameters are as follows: voltage 380 V, frequency 400 Hz, duty cycle 10%, treatment time 30 min.. Uniform and regular porous morphology can be obtained by adding Y (NO_3) _ 3, and the phase structure of the sample prepared without Y (NO_3) _ 3 is the same as that of the sample prepared without Y (NO_3) _ 3, and all of them are composed of NbAl_3 and 纬-Al_2O_3 phases. After hot corrosion in mixed molten salt at 900 鈩，
本文编号：2528938
[Abstract]:In order to optimize the micro-arc oxidation process of aluminized niobium alloy and understand the thermal corrosion resistance of the composite coating, the aluminizing layer was prepared on the niobium alloy substrate by powder embedding infiltration method, and then the outer layer of Al_2O_3 ceramic film was obtained by adjusting the electric parameters of micro-arc oxidation and the content of additive Y (NO_3) _ 3, and the optimum technological parameters were determined. The thermal corrosion resistance of composite coating (MAO-Y/Al/C103) prepared by the best process was compared with that of MAO/Al/C103 prepared without Y (NO_3) _ 3. The results show that the hardness and thickness of the micro-arc oxide film are taken as the main evaluation indexes. The optimum parameters are as follows: voltage 380 V, frequency 400 Hz, duty cycle 10%, treatment time 30 min.. Uniform and regular porous morphology can be obtained by adding Y (NO_3) _ 3, and the phase structure of the sample prepared without Y (NO_3) _ 3 is the same as that of the sample prepared without Y (NO_3) _ 3, and all of them are composed of NbAl_3 and 纬-Al_2O_3 phases. After hot corrosion in mixed molten salt at 900 鈩，
本文编号：2528938
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