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。
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.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2017年第4期45-55,共11页
China Surface Engineering
基金
国家自然科学基金(51371059
51001032)
广西自然科学基金(2014GXNSFCA118013
2016GXNSFDA380022)
广西高等学校高水平创新团队项目(第二批)~~
关键词
铌合金
包埋渗铝
微弧氧化
Y(N03)3
热腐蚀
niobium alloy
pack cementation aluminizing
micro-arc oxidation（MAO）
yttrium nitrate
hot corrosion resistance
