Size-dependent interface adhesive energy and interface strength of nanostructured systems

An analytical model about the size-dependent interface adhesive energy and the interface binding strength was developed based on the size-dependent surface energy and the interface cohesive zone model. The model predicts the enhanced interface binding strength between the nanostructured ceramic coatings and the bulk metallic substrates compared to that between the conventional ceramic coatings with micron-scale grains and the same substrates. The interface binding strength between the ceramic coatings and the metallic substrates was measured by the tensile adhesion test method. The result shows that the interface binding strength of the nanostructured coatings with grain diameter of average 70 nm increases by 86%. The experimental result is in agreement with the theoretical prediction.