Effect of surface topography on micro-mechanical behavior for different metallic materials

Surface topographies of different machined specimens from three typical metallic materials, stainless steel, Ti alloy and Al alloy, have been quantitatively characterized and analyzed to investigate the effect of surface topography on micro-stress concentrations based on the atomic force microscope measurement and finite element simulation. It is found that the surface topography is significantly influenced by the surface treatment method. However, the surface characteristic parameters have shown different variation rules for different metals. It is not only the surface roughness parameters but all characteristic parameters that determine the micro-stress concentrations caused by the surface conditions. Therefore, the integrated influences of surface characteristic parameters on micro-stress behaviors should be considered to estimate the effect of surface conditions on material fatigue performance effectively.