Elastic and plastic deformation of surface asperities and their load-carrying mechanisms during the formation of a real contact area

How the contact behaviours of steel engineering surfaces with different roughnesses ( R a = 0.1, 0.6 and 1.0 μm) are affected by asperity work-hardening deformation regime described here. Large values plasticity index Ψ between 20 50 indicate that all should undergo full plastic deformation. However, in loading range up to yield stress (on nominal area) rough exhibited at least 10% elastic deformation, while for smooth was as much 44%. During loading, increased hardness 63%, 20%. asperities were able carry load resulted 4–10-times-higher pressure than (initial) bulk strength. The proposed mechanisms such an asperity-load-carrying capacity depend on surface roughness. For this is due work-hardening, dominant enhancing load-carrying combined hydrostatic stresses.