The Measurement And Assessment Of Grinding Wheel Grains Based On Vertical Scanning White-light Interferometry

The precision measurement of grinding wheel surface topography is one of thehighlights in grinding research. The topography parameters, including grainprotrusion height, rake angle, grain protrusion area, protrusion perimeter, protrusionequivdiameter, protrusion conformity, and so on are important factors to decide themachinability of grinding wheel and the quality of workpiece surface. Thecharacteristic parameters, acquired from grinding wheel topography detection, areavailable to control the grinding performance, improve the quality of products,forecast and optimize grinding process. Therefore, grinding wheel topographydetection and assessment are very significant to the grinding process. The grindingwheel grains are randomly and with the abrasive wear, falling off and debris blockagein the grinding process. These problems will change the grinding wheel topographyand result in the detection difficulty. Many researches on the detection of grindingwheel topography have been done by scholars at home and abroad. Lacking of aunified detection and assessment method, guidance on practical production remains tobe further improved.This study is focused on using the white light interference theory to detectgrinding wheel topography. The topography recovery and grains recognition wereobtained with continuous sweep images by CCD and a white light interferencealgorithm, those are prepared for assessing the relevant feature parameters. The maincontents are as follows:(1) On the basis of the white light interference theory, the application of verticalscanning white light interferometer (WLI) in grinding wheel topographymeasurement and the system parameters were analyzed.(2) The grain recognition principle based on different reflective characteristicsarising among different materials was discussed, According to that the maximum andminimum intensity difference (I) of diamond is larger than that of bond, this studyused a new method for the grain edge detection of a diamond grinding wheel, which combined an improved Canny operator in Method of Maximum Classes Square Error(called as OTSU) with Ito get the self-adaptive grain recognition threshold. Inaddition, the influences of grains with different bond, the different arrangement ofgrain intervals, and the different light intensities in grain recognition wereinvestigated.(3) In order to characterize the2D parameters (grain protrusion area, grainprotrusion perimeter, grain protrusion equivdiameter, majoraxislength,minoraxislength, grain protrusion conformity) and3D parameters (grain protrusionheight, grain rake angle) of grinding wheel topography,2D and3D feature parametersof a single grain in the surface of a grinding wheel was first studied in detail, and then2D and3D feature parameters of multi-grains were statistically listed.(4) On the premise of grains detection,2D-Motif parameters of Standard ISO:12085were applied to the grinding wheel topography assessment at several differentsections. According to the analysis results, the roughness curve, waviness curve andshape error curve of grinding wheel topography were obtained. The2D-Motifparameters of grinding wheel topography were also figured out with these curves.