Elasto-plastic Properties of Electroplated and Polycrystalline Nickel using Numerical Modelling of the Nanoindentation Test Coupled with an Inverse Method

M. Qasmi, P. Delobelle and F. Richard
Université de Franche-Comté, FR

Keywords: nanoindentation, Young modulus, hardness, grain size, numerical modelling, inverse method

Abstract:
The aim of this paper is a wide investigation of the nano scale of the elastoplastic properties of electroplated Nickel, which is extensively used in the LIGA techniques and polycrystalline hardened and annealed Nickel with large grains diameter. Using instrumented nanoindentation technique, we have obtained the Berkovich's Hardness Hb and the Young's modulus E. These mechanical properties are affected by the current densities used during the electroplating as well as the nature of the substrates and ion chloride density. Experiments were made on Ni samples having a colony diameter d between 0.2 up to 3 micrometers and polyscrystalline of 150 micrometers of diameter. Results obtained through nanoindentation let us show that it exists a Hall and Petch relationship between the hardness Hb and the colony diameter. Numerical modeling of the nanoindentation test using a Finite Element Method (FEM) was done in order to identify the elasto-plastic parameters ofan isotropic behavior law of the material using an inverse method.

Nanotech 2004 Conference Technical Program Abstract