Analysis of fracture roughness parameters of S355J2 steel and EN AW-2017A-T4 aluminium alloy

This article presents an analysis of fracture surface for steel S355J2 and EN AW-2017A-T4 aluminium subjected to fatigue bending, torsion, and bending with torsion. Fracture surfaces were observed using the focus variation microscope, which allows for the acquisition of data sets with large depth of focus. The authors focus on presenting the features of profile roughness parameters on the example of differences between fracture propagation and rupture areas. The researchers are looking for a correlation or ratio between different profile roughness parameters, especially arithmetical mean deviations of the roughness profile Ra and maximum height of the roughness profile Rz, for this case