Papers by Keyword: Auto Correlation Function

Abstract: In this paper, surface morphology characteristics of mechanical finishing (MF) and electrochemical mechanical finishing (ECMF) for 45# steel was investigated. The microcosmic geometry parameters were measured by Surfcorder SE-3H. Compared with original surface, the surface morphology characteristics of the workpiece machined by MF and ECMF have been analyzed with auto correlation function (ACF). The results show that there exist periodicity component in surface profile before and after finishing. The auto correlation curves of ECMF surface have a smaller average period compared with MF surface. The low-frequency component and the mean ripple peak distance of original surface profile are obviously decreased. Furthermore, the ripples and peak density are increased, ECFM have a higher efficiency compared with MF, and the surface roughness Ra is decreased from 0.231μm to 0.032μm in 1 minute. The results indicate that surface quality, material ratio of the profile and wear resistance machined by ECMF are improved obviously.

Abstract: In this paper, surface topography characteristics of electrochemical mechanical finishing (ECMF) for steel was investigated. The scanning electron microscopy (SEM) was used to observe the surface topography. And the microcosmic geometry parameters were measured by Talysurf SLI2000. Compared with original surface, the surface topography characteristics of the workpiece machined by ECMF have been analyzed with altitude density function (ADF) and auto correlation function (ACF). The results show that there exist periodicity component in surface profile before and after finishing. The auto correlation curves of ECMF surface have a smaller average period compared with grinding surface. The low-frequency component and the mean ripple peak distance of original surface profile are obviously decreased. Furthermore, the ripples and peak density are increased, and the surface roughness Ra is decreased from 0.231μm to 0.023μm. The results indicate that surface quality, material ratio of the profile and wear resistance machined by ECMF are improved obviously.

Abstract: With the correlation in stochastic process applied to the experimental results, the surface during grinding and further lapping with abrasive jet finishing (AJF) restricted by grinding wheel was investigated with respect to auto correlation function (ACF) , cross correlation function (CCF) and power spectral density (PSD) analysis. The results indicated that AJF made the surface contour formed periodicity in a small range and removed fluctuation of the surface contour in low frequency greatly. The average spacing of the surface contour decreased and the machined surfaces changed from continuous parallel micro-groove and plough to randomly distributed discontinuous micro-pit with the increase of machining circles. The surface texture became fine and surface roughness was obviously improved. Furthermore, the isotropy surface and uniformity veins both parallel and perpendicular machining direction was attained by the finishing process to improve greatly the wearable capability of the workpiece.