金属基低压等离子喷涂界面的结合性能及微结构研究

Study on Interfacial Bond Properties and Microstructures of Low-Pressure Plasma Sprayed Coatings on Metal Substrates

采用奴氏印痕法、X射线衍射技术 (XRD)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、X射线能量散射谱 (EDS)等方法研究了Ni/Fe ,Cu/Ni低压等离子喷涂材料的喷涂界面结合性能及微结构特征。喷涂界面的结合性能与其微结构、微成分特征密切相关。Ni/Fe试样具有结合良好的界面 ,界面层为在晶态 (Fe ,Ni)氧化物上弥散分布着纳米级 (Fe,Ni)金属间化合物细晶的结构 ,界面区有明显的元素扩散 ;Cu/Ni试样喷涂界面层为典型的非晶相 ,界面区未见明显的元素扩散。不同微观特征的喷涂界面对应的宏观界面结合性能有明显差异 ,Ni/Fe喷涂界面结合强度明显优于Cu/Ni喷涂界面。对Ni/Fe。

The microstructural characterization of coatings and interface for two materials, Ni/Fe and Cu/Ni, deposited by low pressure plasma spraying method, was studied by means of scanning electron microscopy(SEM) and transmission electron microscopy(TEM) combined with energy dispersive X ray spectroscopy(SEM). The adhesion between coatings and substrates was measured by means of Knoop interfacial indentation testing. Moreover, X ray diffraction was used for the residual stress evaluation in coatings. The results show that interfacial microstructures have strong influence on the mechanical properties. Cu/Ni interface is weak link with oxide amorphous phase. Ni/Fe interfacial layer consists primarily of Fe and Ni oxide crystalline phase, dispersed with spotlike microcrystals, and the interfacial interdiffusion is detected. All these suggest that the different interfacial microstructures can result in different interfacial bond strength and interfacial cracking.