Study on the deformation mechanics of hard brittle coatings on ductile substrates using in-situ tensile testing and cohesive zone FEM modeling

Comparison of damaging behavior of oxide scales grown on austenitic stainless steels using tensile test and cyclic thermogravimetry

“…Nevertheless, at some point, localized plastic deformation of the metal at the crack root happens, diminishing the strain transferred to the oxide film. As a result, there is not enough available energy for new cracks to initiate [30]. Those results confirm that the Cr-rich thinner oxide scale thermally grown on AISI 304L is more protective, since it is more resistant and more adherent to the metal than the oxide scale grown on AISI 303.…”

In-situ SEM study of crack initiation, propagation and interfacial debonding of Ni-P coating during tensile tests: Heat treatment effect

“…It brings out tunnel cracks emanating from the top surface of the coating toward the inner wall and stopping at the substrate. Thus, it is very interesting to observe a strong adhesion of the coating to the substrate, which can be deduced from the high brittleness and the less strength of the coating [20,32,41]. These cracks are very opened and present flat faces due to Mode I crack opening.…”

“…This remark is intriguing since numerous studies have interpreted that the spallation occurs when the surface of substrate is more rugged and developed than the coating [17,20]. Hamad et al [32] revealed that the stress transferred from the substrate to the coating segments was dependent on the elastic and elastic/plastic properties of the coating and the substrate. Furthermore, the segmentation of the coating and the delamination depended strongly on the film and substrate properties.…”

Determination of interfacial adhesion energies of thermal barrier coatings by compression test combined with a cohesive zone finite element model

“…For simplicity, critical fracture energies in normal and shear directions were assumed the same, i.e., G nc ¼ G sc , which is between 70 and 150 J/m 2 (Guo et al, 2005;Kim et al, 2007b). The shape of the traction-separation law was defined by d ratio ¼ d 0 i =d f i , and its value was taken to be 0.25 (Rehman et al, 2012). It is worth noting that the cohesive zone model exhibits a softening behavior, which usually results in serious convergence problems in finite element simulations.…”