(1.Beijing Advanced Innovation Center for Material Genetic Engineering, University ofScience and Technology Beijing, Beijing 100083, China)(2.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)(3.Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China)
Brittle films (or coatings) are used to protect ductile metal substrates from damage induced by the harsh environments, thus increasing their service life. However, the fracture of brittle films can cause the cracking of ductile metal substrates, which will seriously threaten the safety of metal bearing structures. Thus, it is necessary to understand the nature of this phenomenon and build the related countermeasures. In this review, we will introduce the origin, mechanism and related countermeasures of this phenomenon “film induced cracking of substrates”. The combination of short range coatingsubstrate interaction and fracture of coating inhibit the local plastic deformation of ductile substrate near interface, causing their cleavage cracking. Lowering the mismatch between film and substrate, the fracture probability and the crack velocity in films contribute to preventing the occurrence of this phenomenon.