超音速等离子喷涂纳米结构Al_2O_3-13%TiO_2涂层的形成机理

Formation mechanism of nanostructured Al_2O_3-13%TiO_2 coating fabricated by supersonic plasma spraying

采用超音速等离子喷涂方法制备了含纳米结构的Al_2O_3-13%TiO_2涂层。对涂层的相变过程和显微结构的形成进行了分析。结果表明,涂层主要由完全熔融和不完全熔融两部分组成,不完全熔融的喂料中部分α-Al_2O_3未发生相变。涂层形成过程中晶粒熔融长大到100 nm以上。Al_2O_3和TiO_2之间存在Al_2TiO_5共晶组织和界面间原子尺度键合结构。

Nano-structured Al_2O_3-13%TiO_2 coating was fabricated by supersonic plasma spraying. Phase transformation process and microstructure formation of the coatings were characterized. The results show that the coating mainly consists of molted and part-melted structure,and some α-Al_2O_3 in the part-melted feedstocks keep original phase. The grain size can grow up to above 100 nm during the coating formating process. There is eutectic phase of Al_2TiO_5 and atom-sized linkage structure between Al_2O_3 and TiO_2.