Characterization of mechanical properties of machined surface by nanoindentation — Part 1: Simulation of indenter geometry effects

Summary, in English

Abstract in Undetermined
The machined subsurface often undergoes severe deformation and possible microstructure changes in a small scale subsurface layer. Mechanical behavior of this shallow layer is critical for component performance such as fatigue and wear, thus characterization of the mechanical behavior of the machined subsurface in terms of micro/nano hardness, modulus, residual stresses and change of microstructure is vital. The mechanical behavior of this shallow layer is often hard to measure using traditional material testing, due to the small size of subsurface deformation region. With the nanoindentation method, mechanical behavior (nanohardness and modulus) at the microscale in subsurface can be measured. However in nanoindentation, there are many parameters that significantly affect measurement reliability and thus may lead to errors in the evaluation of results. As the part of project of characterization of mechanical properties in machined surface by nanoindentation, the indenter geometry effects on elastic-plastic behaviour was investigated with use of finite element (FE) method in present work. The elastic-plastic behaviour as the response to indenter geometry, such as tip radius and angle, are simulated in the study by use of von Mises material model. The hardness and the Young modulus of the material are determined combining both analytical and numerical methods and their dependence on the tip radius and angle is investigated.