硬质薄膜在工程应用中经常承受高载荷作用。在接触载荷下,薄膜/基底体系通常产生剪切分层破坏和法向分层破坏,并直接影响材料的可靠性。硬质薄膜中较大的残余应力对界面分层破坏影响不容忽视。该文基于内聚力模型,采用有限元方法模拟残余应力对压头诱导的硬质薄膜/韧性基底界面分层破坏的影响规律;给出在不同残余应力下薄膜/基底界面分层破坏时的临界压入深度以及临界载荷;获得考虑残余应力时硬质薄膜/韧性基底界面分层破坏失效图,进而对薄膜材料的工程应用和采用压痕法测量界面结合性能提供指导。
Hard thin films are often subjected to high loadings in the engineering applications. The shear and normal delaminations formed in the system including hard thin films and ductile substrates under the contact loading affect the reliability of the materials. The great residual stress in the hard thin films influences the interface between the films and the substrates, even resulting in the failure of the interface. In this paper, the effect of residual stress on the interface delamination of the hard thin films on ductile substrates is simulated by the cohesive model and finite element method. The critical indentation depth and critical load are obtained under alterable residual stress when the shear or normal delamination occurs, indicating the delamination mechanism induced by indentation. The failure mechanism map for the interface between the hard thin films and the ductile substrates is indicated when the residual stress is considered. This provides guidelines for engineering applications of thin films and the measurement of bonding behavior at the interface by using indentation.