Experimental study on the characterization of worn surface topography with characteristic roughness parameter

The fractal dimension and scale coefficient of surface profiles were calculated using the structure function method. Studies show that fractal dimension or scale coefficient is not optimum in characterizing rough surfaces. In consideration of this case, a fractal parameter called the characteristic roughness is put forward by combining the profile fractal dimension and the scale coefficient. Its definition and calculation expression are given. Running-in wear tests were conducted by using a thrustwasher type tester, and surface topographies were measured in the same area of the test specimens at different wear times. Experimental results show that the characteristic roughness parameter is not only more objective but also more sensitive to characterize wear surfaces during the running-in process than fractal dimension or scale coefficient.