Stress-strain state of gradient materials under inclined contact load

The paper provides research data on the stress-strain state at the interface of a low-carbon steel substrate and its surfaced coating under static inclined contact load. Using the finite element method, it is shown that the distribution of normal stresses at the contact interface depends on the ratio of elastic constants and on the ratio of normal and tangential stress components. For the substrate and coating with equal elastic moduli at equal normal and tangential loads, a tensile stress zone is found at the contact interface, which is more evident with decreasing the ratio of normal to tangential loads and the elastic modulus of a surfaced layer. For hard coatings, compressive stresses are detected at the contact interface. The data suggest that the elastic modulus of surfaced coatings should ten times that of the substrate.