摘要
采用喷雾造粒、化学冶金包覆和固相合金化技术制备了Ni Co Cr Al Y/Al2O3复合粉体,并采用超音速火焰喷涂技术制备了Ni Co Cr Al Y/Al2O3复合涂层。采用SEM、XRD和马弗炉对该涂层和粉体的显微结构和抗氧化性能进行了研究。结果表明,Al2O3颗粒表面均匀致密的包覆着一层Ni Co Cr Al Y合金,Ni Co Cr Al Y/Al2O3复合粉体呈球形,颗粒大小均匀。超音速火焰喷涂Ni Co Cr Al Y/Al2O3复合涂层与基体结合良好,涂层孔隙率仅为(0.41±0.05)%。涂层抗氧化性能良好,氧化动力学曲线分为3个阶段:大斜率直线阶段,系数较小的抛物线阶段和斜率几乎为零的直线阶段。涂层在850℃氧化96 h以后,涂层氧化增重为2.5 mg·cm-2左右。复合涂层中氧化物膜的形成和Al2O3硬质相的加入是涂层抗氧化性能提高的主要原因。
The NiCoCrAlY/Al2O3 composite powder was prepared by the technology of spray granulation, chemical and metallurgical coating and solid state alloying. The NiCoCrAlY/Al2O3 composite coating was prepared by high velocity oxygen fuel （HVOF） spraying technology. The microstructure and oxidation resistance of the powder and coating were studied by SEM, XRD and muffle furnace, respectively. The results show that theAl2O3 is coated with NiCoCrAlY alloy. The NiCoCrAlY/Al2O3 composite powder is round and well-distributed. The NiCoCrAlY/Al2O3 composite coating exhibits excellent combination with the substrate and the porosity of the coating is only （0.41 ± 0.05） %. The coating has excellent oxidation resistance. The oxidation kinetics curve of the coating can be divided into three stages, i.e. severely slopeing line, parabolic and slightly parabolic. The value of oxidation weight gain is about 2.5 mg·cm-2 after oxidation at 850 ℃ for 96 h. The main reasons for the improvement of oxidation resistance of the composite coating can be attributed to the formation of oxide film and the addition ofAl2O3.
出处
《金属热处理》
CAS
CSCD
北大核心
2015年第8期88-91,共4页
Heat Treatment of Metals
基金
河北省自然科学基金(E2015105068)
唐山市科技计划项目(14130286a)
唐山学院材料科学与工程重点学科(TSC2013003)
