|
The microstructures and mechanical properties of dc-magnetron-sputtered Ag/Cu, Ag/Co and Ag/W nanoscale multilayers were evaluated by X-ray diffraction, scanning electron microscopy and nanoindentation. The effect of plasticity mismatch on mechanical properties of these multilayers was investigated. The maximum hardness of Ag/Cu multilayers is 70% larger than the rule-of-mixture value, and that of Ag/Co multilayers is only 23% larger than the rule-of-mixture value, however, the hardness of Ag/W multilayers is far less than the rule of mixture value. The difference of the hardness enhancement may be attributed to deformation localization due to the plasticity mismatch between two component elements, i.e, multilayers with larger plasticity mismatch have lower hardness enhancement. For all the three multilayers, the elastic modulus decreases with decreasing modulation period due to the increase of compliant interface. |