Yaguchi T, Kamino T, Sasaki M, Barbezat G, Urao R
School of Engineering, Ibaraki University, Narusawa-cho, Hitachi, Ibaraki 316-0031, Japan
Microsc Microanal. 2000 May;6(3):218-223.
A focused ion beam (FIB) technique was applied to cross-sectional specimen preparation to observe an interface between a plasma sprayed coating and an aluminum (Al) substrate by transmission electron microscopy (TEM). The surface of the sprayed coating film has a roughness of several tens of microns. Sputter rates for the coating film and the substrate are greatly different. The rough surface and the difference in sputter rate cause problems in making TEM specimens with smooth side walls. The top surface of the coating film was planerized by the FIB before fabricating the TEM specimen. The interfaces were investigated by TEM and energy-dispersive X-ray (EDX) analysis. The TEM observation revealed that there is a 10 nm thick amorphous layer at the interface between the coating film and substrate. The coating film consists of two kinds of sublayers with bright and dark contrast. The bright contrast sublayers were amorphous layers with thickness of 2 approximately 10 nm. The Al/Fe X-ray intensity ratio was larger in bright contrast sublayers than that in dark contrast sublayers.
采用聚焦离子束（FIB）技术制备横截面试样，通过透射电子显微镜（TEM）观察等离子喷涂涂层与铝（Al）基体之间的界面。喷涂涂层薄膜表面粗糙度为几十微米。涂层薄膜和基体的溅射速率差异很大。粗糙的表面和溅射速率的差异导致制备具有光滑侧壁的TEM试样时出现问题。在制备TEM试样之前，用FIB对涂层薄膜的顶面进行了平面化处理。通过TEM和能量色散X射线（EDX）分析对界面进行了研究。TEM观察表明，在涂层薄膜与基体的界面处存在一个10nm厚的非晶层。涂层薄膜由具有明暗对比度的两种子层组成。亮对比度子层为非晶层，厚度约为2至10nm。亮对比度子层中的Al/Fe X射线强度比大于暗对比度子层中的Al/Fe X射线强度比。
