摘要
为了提高铌合金的高温抗氧化性能,首先采用阴极匀速旋转电沉积法在铌合金表面制备了钼层,然后通过包埋渗硅获得硅化物复合涂层。研究了沉积态钼层和硅化物涂层的形成和微观组织结构,对比分析了有或无涂层C103合金的高温氧化行为。结果表明,阴极匀速旋转法使沉积的电流效率提高1倍多,钼层呈胞状结构、以非晶形式存在。经包埋渗硅后,生成了表层以MoSi_(2)为主、中间层为NbSi_(2)的复合涂层,涂层与基体结合良好。经1200℃氧化10和30 h后,涂层试样的氧化抛物线速率常数分别为1.83×10^(-2),8.08 mg^(2)·cm^(-4)·h^(-1),与之相比,裸合金的氧化抛物线速率常数则为5.87×10^(3) mg^(2)·cm^(-4)·h^(-1),而且仅氧化10 h裸合金即出现了严重粉化;在高温氧化过程中,复合涂层表面生成SiO_(2)垢层,具有优良的抗高温氧化性能。
In order to improve the high temperature oxidation resistance of niobium alloy,a molybdenum layer was firstly prepared on the surface of niobium alloy by electrodeposition method with uniform rotating cathode,and then the silicide composite coatings were obtained by the halide activated pack siliconizing.The formation and microstructure of as-deposited molybdenum layer and silicide coating were studied,and the high temperature oxidation behavior of C103 alloy with or without coating was compared and analyzed.The results show that the current efficiency during electrodeposition is twice as high as that by conventional electrodeposition.The prepared molybdenum layer is amorphous with a cellular structure.After pack siliconizing,mainly MoSi_(2) and NbSi_(2) predominate the surface layer and intermediate layer of the composite coatings,respectively,and the composite coatings exhibit a strong interfacial bonding to the substrate.Thermally exposed at 1200℃ for 10 and 30 h,the coated samples show parabolic rate constants of 1.83×10^(-2) and 8.08 mg^(2)·cm^(-4)·h^(-1),respectively.By comparison,a higher parabolic rate constant about 5.87×10^(3) mg^(2)·cm^(-4)·h^(-1) is detected in the bare alloy,and pesting oxidation is found in the bare alloy after only 10 h exposure.The composite coatings present excellent resistance to high temperature oxidation due to the formation of SiO_(2) surface scales during thermal exposure.
作者
杨维维
张有才
雷声远
凌奎
赵小莲
李伟洲
Yang Weiwei;Zhang Youcai;Lei Shengyuan;Ling Kui;Zhao Xiaolian;Li Weizhou(Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,Nanning 530004,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2022年第5期1797-1804,共8页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51371059)
广西自然科学基金(2016GXNSFDA380022)
广西高等学校高水平创新团队项目(第二批)
广西科技重大专项(桂科AA18118030,AA17204100)
广西有色金属及特色材料加工重点实验室基金(GXYSSF1804)。
关键词
铌合金
电沉积
复合涂层
高温氧化
niobium alloy
electrodeposition
composite coating
high temperature oxidation
