Measurement of the mechanical properties of silver and enamel thick films using nanoindentation

Abstract

Analyzing material properties of thick film multilayers deposited onto soda-lime silicate glass raises several challenges since these layers can exhibit complex multiphase microstructures. The mechanical properties of sintered silver and glass enamel thick films have been investigated using nanoindentation methods to provide deeper understanding of the composite stack in-service failure mechanisms. The spatial distribution of the Young's modulus and hardness have been studied on the cross section of the layers to avoid the influence of surface roughness and underlying glass substrate. The apparent indentation fracture toughness of the layers has been evaluated via SEM and high-resolution surface topography images of the hardness imprints. A modified Berkovich indenter has been employed to study the elastic and plastic deformation regimes while the fracture deformation regime has been investigated using a cube-corner indenter. In the enamel layer, copper chromite spinel pigments were found to provide a beneficial effect on the films mechanical performance due to their significantly higher elastic, hardness, and toughness properties compared to the surrounding amorphous phase. The amorphous phase of the enamel layer and the glass substrate has comparable mechanical properties, while the fracture toughness of sintered silver is higher, partially explaining the failure initiation in the enamel layer.