Quasi-static and dynamic compressive deformation of a bulk nanolayered Ag-Cu eutectic alloy: Macroscopic response and dominant deformation mechanisms

Nanostructured multilayered material systems offer an attractive method of increasing material strength. This work examines the response of a bulk eutectic silver-copper material (Ag60Cu40, subscripts indicating atomic percent) which has a hierarchical structure of alternating Ag and Cu layers with thicknesses down to 50 nm. The hierarchical structure consists of two primary arrangements of layers, eutectic colonies of parallel layers, most commonly found at the material interior, and “grains” consisting of alternating Ag and Cu layers which emanate from a central region in a radial pattern, most commonly found at the material exterior surface. We show that the hierarchical structure causes a significant increase in the measured strength response when comparing the Ag60Cu40 response to that of the constituent materials in their bulk nanograined or micrograined form. The deformation mechanisms of this material are studied under compressive loading over the quasi-static and dynamic regime (10−3-103 s−1) with strain between 5% and 50%.