Numerical Study on the Effects of Equi-biaxial Residual Stress on Mechanical Properties of Nickel Film by Means of Nanoindentation

In this paper, mechanical properties of Nickel film under residual stress have been systematically examined by finite element method in nanoindentation. It was found that load-displacement curves shifted under elastic residual stress and residual stress exceeded the yield stress for fixed indentation depth. Indentation profiles changed monotonously with compressive and tensile stresses at peak force which determinates contact area observed directly by finite element modeling (FEM). The elastic residual stress has an effect slightly on the hardness but residual stress exceeded the yield stress shows a remarkable effect in nickel film. The hardness increased when residual stress exceeded the yield stress increased under tensile and compressive stress applied to specimen. The relationship between residual stress and hardness was linear. It was found that residual stresses didn't affect elastic modulus whether elastic residual stress or plastic stress was applied to specimen.