Characteristics of Friction-introduced Acoustic Emission Based on the Surface Roughness

Surface roughness is one of the important factors that affect friction. The friction is a very complicated dynamic process. Measuring the dynamic process is very difficult. To investigate the influence of surface roughness on the friction, acoustic emission technique was used to detect the friction state of surface with different roughness. The result indicates that the friction coefficient increased with the increasing surface roughness. When the surface roughness reached a certain value, the friction coefficient decreased with the increasing surface roughness. The variation of the signals of acoustic emission (energy, amplitude, ring count) with surface roughness was the similar with the variation of the friction coefficient with surface roughness. There were the close relations between the signals of acoustic emission and surface roughness. It is feasible that the friction state can be measured and inspected with acoustic emission signal.