Structure and mechanical properties of Cu-Ag nanocomposite films

摘要

Metal-metal nanocomposites are studied to answer the questions of their formation mechanism, morphological development and related physical properties. The films were prepared by combinatorial co-deposition of Cu and Ag in a wide composition interval using thermal evaporation in high vacuum. Films close in composition to the eutectic have grain size below 10 nm and display strong <111> texture. Nanoindentation data show that Cu-Ag nanocomposite films have a maximum of hardness reaching 4 GPa around 20 at.% of Ag, four times greater than either of the building components. The composition dependence of the Young's modulus obeys the rule of mixtures, while their HIE ratio values are about 0.02 and practically constant in 10-60, at.% Ag content range.