涂层界面结合强度检测研究(Ⅰ):涂层结合界面应力的理论分析

Study on the determination of interfacial binding strength of coatings (Ⅰ):theorctical analysis of stress in thin film binding interface

利用激光划痕测试法和弯曲应力理论,建立了涂层结合界面应力的理论模型,推导出结合界面剪应力、正应力和剥离应力分布公式,分析了结合界面应力产生的机理.理论分析结果表明,界面正应力主要集中在界面中心区域内,而在界面边缘附近,正应力迅速下降,在界面边缘处其值降为0;剪应力和剥离应力主要集中在界面边缘区域内,在远离界面边缘区域,剪应力和剥离应力则迅速下降;涂层中正应力和涂层厚度、基体厚度以及杨氏模量无关,界面间剪应力以及剥离应力随涂层厚度增加而增加,并且由涂层与基体厚度以及杨氏模量所共同决定.

The theoretical model of stress in film binding interface is established with the help of laser scratch testing （LST） and the theory of bending stress, the distribution formulae of stress such as shear stress, normal stress and stripping stress are deduced, and the mechanism of stress forming in binding interface is analyzed. It is shown that the normal stress of interface is mainly concentrated on interface center region, it decreases quickly near the interface edge, becomes zero at the interface edge. Shear stress and stripping stress are mainly concentrated in the interface edge, they decrease quickly away from the edge. Normal stress of film is not related with film thickness, matrix thickness and Young＇s modulus, the shear stress and stripping stress increase with film thickness, and they are determined by thickness of film and matrix and Young＇s modulus.