Interface characteristics of Al_2O_3－13%TiO_2 ceramic coatings prepared by laser cladding  

激光熔覆Al_2O_3–13%TiO_2陶瓷涂层的界面特征(英文)

作　　者：高雪松[1,2] 田宗军[2] 刘志东[2] 沈理达[2] 

机构地区：[1]东南大学机械工程学院,南京210018 [2]南京航空航天大学机电学院,南京210016

出　　处：《Transactions of Nonferrous Metals Society of China》2012年第10期2498-2503,共6页中国有色金属学报（英文版）

基　　金：Project (59975046) supported by the National Natural Science Foundation of China

摘　　要：Al2O3-13%TiO2 （mass fraction） coatings, prepared by laser cladding on nickel-based alloy, were heated using high frequency induction sources. The coating microstructure and the interface between bond coating and ceramic coating were characterized by SEM, XRD and EDS. The results show that two-layer substructure exists in the ceramic coating： one layer evolving from fully melted region where the sintered grains grow fully; another layer resembling the liquid-phase-sintered structure consisting of three-dimensional net where the melted Al2O3 particles are embedded in the TiO2-rich matrix. The mechanism of the two-layer substructure formation is also explained in terms of the melting and flattening behavior of the powders during laser cladding processing. The spinel compounds NiAl2O4 and acicular compounds Cr2O3 are discovered in the interface between bond coating and ceramic coating. It proves that the chemical reactions in the laser cladding process will significantly enhance the coating adhesion.利用高频辅助激光熔覆技术在镍基合金上制备Al2O3-13%TiO2(质量分数)陶瓷涂层。采用SEM、XRD和EDS等方法分析陶瓷涂层的微观结构和陶瓷层与粘结层之间的结合界面。结果表明:陶瓷层出现了完全熔化区和液相烧结区双层结构,其中,完全熔化区颗粒充分烧结长大,而液相烧结区则出现了三维网状结构,该三维网状结构由熔化的TiO2相包裹Al2O3颗粒形成。通过激光熔覆作用下的粉末熔化和扁平化行为解释双层结构形成机理。同时,在陶瓷层与粘结层的结合界面上发现具有尖晶石结构的NiAl2O4和针状结构的Cr2O3,证明在激光熔覆过程中发生的化学反应可以有效增加陶瓷层与粘结层的结合强度。

关 键 词：ceramic coating nickel alloy laser cladding Al2O3-TiO2 high frequency induction 

分 类 号：TG174.453[金属学及工艺—金属表面处理]