Relative contact pressure - Dependence on surface roughness and Vickers microhardness

An explicit expression for the contact hardness and the relative contact pressure is developed. This expression is simple and clearly shows the dependence of the contact hardness and the relative contact pressure upon the Vickers microhardness correlation coefficients and the surface roughness parameters. Parametric studies of the contact conductance are performed, and it is shown that theoretical predictions and experimental data are in good agreement. Nomenclature = mean contact radius, m = apparent contact area, m2 = constant for Vickers microhardness correlation ah = dimensionless conductance, C = - = Vickers indentation diagonal, m = conductance, W/mZ.K = bulk hardness, MPa = contact microhardness, MPa = Vickers microhardness, MPa = thermal conductivity, W/m.K = harmonic mean thermal conductivity, W/m.K = mean absolute asperity slope = constants in Eqs. (20) and (21) mks