PREDICTION OF ROUGHNESS PARAMETERS OF THE TREATED SURFACE TAKING INTO ACCOUNT A DRESSING METHOD OF THE GRINDING WHEEL

The paper presents the results of theoretical and experimental studies of the effect of grinding wheel dressing methods on the height and pitch parameters of the roughness of the part surfaces treated. Analytical dependences are presented for calculating the roughness parameters of the surfaces of workpieces treated by grinding after various methods of dressing abrasive wheels, the reliability of which is confirmed by experimental studies. It is found out that in order to ensure surface roughness with a height parameter Ra of less than 0.4 microns, it is recommended to use an abrasive wheel dressing with a single-crystal diamond tool (diamond in a rim, diamond pencil). To ensure roughness with the parameter Ra in the range of 0.4 – 0.8 microns, it is recommended to dress the grinding wheel with a roller or a multi-crystal diamond pencil. Dressing the grinding wheels with carbide discs will ensure surface roughness after treatment with Ra parameter of more than 0.8 microns. It is found out that the radius of rounding of the tops of abrasive grains has a significant effect on the step parameters of the roughness of workpiece surfaces treated by grinding. At the same time, the average step value of the roughness profile irregularities along Sm mean line is 2-3 times greater than the average step value S of the local protrusions of the roughness profile. Therefore, the formation of fine irregularities of the surface with a given ratio of height and pitch parameters is possible by selecting the grain size of the grinding wheel, which affects the radius of rounding of the grain vertices. The paper presents scientifically based recommendations on the choice of methods for dressing abrasive tools and the conditions for maintenance of the roughness parameters of the workpiece surfaces processed by grinding wheel face.

grinding, wheel, dressing, tool, tip, abrasive grain, parameters, roughness