The size effect in adhesive contact on gradient nanostructured coating.

The adhesive contact problem between a rigid cylindrical punch and gradient nanostructured (GNS) coating is investigated by considering the size effect. The laminated plate model is applied to characterize the material properties of GNS coating in plane strain couple stress elasticity. By using the Fourier integral transform and transfer matrix method, the governing singular integral equation(s) for two dimensional adhesive contact problem are obtained. Numerically calculated results are presented to analyse the effect of characteristic material length, the adhesion parameter and nonhomogeneous parameter on the mechanical response of GNS coating for the adhesive contact problem. The paper explored the nano scale contact of GNS coating with shear modulus varying as a function of depth according to an exponential function or the power law function. The present results provide a way to improve the contact deformation and damage of Nano-Electromechanical System (NEMS) by adjusting the gradient index of GNS coating.