Multifractal analysis of three-dimensional surface topographies of GCr15 steel and H70 brass during wear process. (September 2018) - Zuo, Xue
Highlights: A multi-stage test method was proposed to study the surface evolution. The 3D topographies of mating surfaces were studied simultaneously. Multifractal analysis on GCr15-H70 wear surface was performed. Abstract: The variation of three-dimensional topographies of GCr15 steel and H70 brass during wear process was studied by multifractal method. A multi-stage test method was proposed to obtain the worn surfaces of friction pair at different wear time. The tests were performed on a ring-on-disc tribometer. The three-dimensional (3D) topographies of ring and disc were measured by laser confocal microscopy. Box-counting method was applied to compute multifractal spectrum, spectrum width Δ α and spectrum difference Δ f ( α ) of counter surfaces. All the spectra of mating surfaces are presented as parabolic curve, which indicates that the worn surfaces have the characteristics of multifractal. The Δ α and Δ f ( α ) of disc surfaces decrease at first, then stabilize at a small value and finally increase rapidly. Those of ring surfaces increase at first, then maintain at a small value and finally increase gradually. The multifractal study of 3D surface topographies reveals the singularity and nonlinear behavior of the friction system.