气相沉积硬质薄膜韧性评价方法——压入法  

On the Indentation Method to Evaluate PVD Hard Coating Fracture Toughness

作　　者：杜军[1] 王尧[1] 朱晓莹[1] 

机构地区：[1]装甲兵工程学院再制造技术国家重点实验室,北京100072

出　　处：《测试技术学报》2016年第2期125-131,共7页Journal of Test and Measurement Technology

基　　金：国家青年自然基金资助项目(51102283;51401238)

摘　　要：评价气相沉积硬质薄膜的韧性具有重要的工程意义.本文讨论了压入法评价硬质薄膜韧性的原理、方法和参数选择.压入法的原理是载荷导致裂纹形核、扩展,最终形成压痕周围的径向裂纹,而断裂韧性和裂纹之间存在对应关系.压入法的方法是比较压痕形貌特征,其主要影响因素有基体和载荷.对于韧性基体（如金属）,小载荷时硬质薄膜与金属同步塑性变形;大载荷下薄膜破裂,但这种情况可能是结合失效破裂,并不反映薄膜的韧性.对于脆性基体（如硅片）,小载荷时裂纹会在Si片中形核,并扩展到薄膜中,形成压痕对角线径向裂纹;大载荷时薄膜会严重破裂.定量评价薄膜韧性时,一般采用硬质薄膜/Si片体系,以0.98～9.8N载荷压入脆性基体,采用纳米压入仪测定薄膜的硬度和弹性模量,采用显微镜测量径向裂纹的长度,利用Lawn公式计算得到断裂韧性值.It is valuable to assess the fracture toughness of Physical Vapor Deposition（PVD）hard coatings.Using indentation to evaluate the principles,methods and preferences of Hard film toughness was discussed.The principle of indentation method is that nucleation and expansion are caused by crack,and ultimately forming the radial cracks around the indentation.There is a correspondence between the fracture toughness and crack.he method of indentation is to compare the indentation morphology,the main factors are the substrate and load.For ductile substrate（e.g.metal）,the hard coating can deform plastically and synchronously with substrate at small load,and form crack at high load.But this could be adhesion failure more than cohesion failure.For brittle substrate（e.g.Silicon wafer）,the micro-crack nucleate easily in Si and propagate into hard coating.Radical length along indent diagonal direction clarify itself to be fracture toughness measurement under small load,and serious rupture appears under high load.For quantitative evaluation purpose,Lawn equation are ideal model for hardness coating/brittle substrate system,the load range are 0.98～9.8N,the hardness and elastic modulus could be evaluate by nano-indentation,the radical crack length could be measured by microscope.

关 键 词：气相沉积 硬质薄膜 断裂韧性 压入法 

分 类 号：TG178[金属学及工艺—金属表面处理]