Authors: I. Hussainova, I. Jasiuk
Affilation: Tallinn University of Technology, Estonia
Pages: 152 - 155
Keywords: nanoindentation, composites, hardness, reliability, size effect
Development of advanced composites requires a detailed knowledge of their constituents’ properties as they are often somewhat different from the materials at their bulk form. In the present study, the nanoindentation techniques of two different loading scenarios have been applied to chromium carbide based and nickel – chromium alloy bonded cermets to evaluate the micromechanical properties of the constituent phases. The aim of this paper is to report the experimental data on modulus of elasticity and hardness of cermets’ constituents taking into consideration the indentations size effects and uncertainties in the projected area calculation due to pile – ups of the binder alloy. Approximation of the pile-up contact area as a semi-ellipse has been applied to calculation of the hardness and modulus of elasticity. Size effect observed for constituents’ properties was eliminated by proper calibration of the device. Differences in hardness and module between constituents in their bulk form and constituents in composite give evidence of influence of the residual stresses and spurious phase formation during sintering and of the fact that phases have dissimilar composition as compared to bulk materials. Therefore, in design of new composites the real phases’ properties should be taken into consideration.