Research on full-element characterization of honed surface roughness based on image-based Abbott-Firestone curves

High-strength steel bore parts such as valve spools, valve sleeves play an important role in industrial production. Most of the existing evaluations of the bore surface quality of the hydraulic valve bore system parts are based on Ra. But similar surfaces may be obtained under different process parameters, and the Ra values of these surfaces are close to each other, so it is difficult to comprehensively reflect the surface characteristics. Therefore, a full-element characterization of roughness based on image-based Abbott-Firestone curves (FIAF) has been proposed. The least squares method and the Butterworth high-pass filter with adaptive cut-off frequency were designed to process the acquired honed surface image. The FIAF curve was resolved to obtain the curve parameters to fully characterize the roughness of the honed surface. The results showed that this method could comprehensively characterize different regions of the hole surface quality, and had a higher sensitivity to variations of structure.In the case of Ra close (within only 0.004 μm difference), the FIAF parameters are still significantly different. When the Ra of the two groups of surfaces differed by only 0.001 μm, the IM1 was 1.8781 and 0.605, respectively, with the latter group having a smaller percentage of the peak area. This group will be removed by wear faster under the same operating conditions, thus reducing the initial break-in time of the hydraulic valve bore system parts. Therefore, the use of the FIAF method can further evaluate the machined surface and guide the selection of process parameters, thus providing theoretical support for the precision machining of hydraulic valve bore system parts.