SIZE EFFECTS IN ELECTRODEPOSITED NI - COATINGS

摘要

Polycrystalline Ni materials with grain sizes less than 100 nm (nano crystalline NC) and with grain sizes in the micrometer range (micro crystalline MC) in form of thin films have become important in many technologies due to their improved physical, chemical and mechanical properties. Usual the mechanical properties of such coatings are described by a Hardness value and a Young's modulus measured by Instrumented Indentation Testing (IIT). The behavior of such coatings during indentation test is influenced by different size effects having their representative length scale - grain size, coating thickness, length that characterizes the depth dependence of the hardness (Indentation Size Effect ISE). To estimate realistic values for the intrinsic coating Hardness and Young's modulus all size effects have to be considered.