Finite Element Analysis On Mechanical Response Of DLC Film

Coated materials are extensively used in many areas with the fast development of coating technology. The DLC film which has extensive applications is hard film, widely used in aerospace, microelectronics, iatrology, optics, acoustics and other areas because of its good physical and chemical properties.Coated materials, especially the hard films, often has failure because of the generation, expand of the cracks in the interface of film and substrate, delamination of the film. Large number of studies show that the failure is caused by the change of stress state of the film/substrate system when the system is applied pressure and friction, and the change, to a large extent, is depended on the material properties of film and substrate and the coating process. Understanding the distribution of internal stress of film system, and then, finding the method to enhance the bonding strength of film and substrate become a growing concern.This paper calculates the internal stress state of the DLC film system applied normal and tangential forces using the finite element method, analyses the influence of film thickness, friction coefficient and film elastic modulus to internal stress state. The internal stress of the system which has interface crake is also simulated. The influence of the length and width of the crack is analysed.