Study of the Scaling Effect of Cutting Elements of the Abrasive Wheels’ Discretized Working Surface on Geometric and Physical-Mechanical Parameters of the Surface Layer Quality of Ground Parts

The paper proves that reducing the scale of the abrasive wheel’s working surface discretization decreases the spindle unit’s vibration level and creates processing conditions similar to ultrasonic vibrational grinding. It was established that the boundaries of the regions of parametric instability of the elastic system of a surface grinding machine and undesirable structural changes in the surface layer of the machined part have a similar character. This means that the geometric and physicomechanical quality indicators of the surface layer of the part during the grinding operation can be stabilized by scaling the macro-relief of the working surface of the discontinuous circles (proportional reduction of the lengths of the protrusions and recesses) and reducing the discretization step of this surface while simultaneously reducing the numerical value of the ratio of the width of the recess to the length of the protrusion within the specified limits 0,3 \(\le N \le\) 0,5. It was established that interrupted cut-off wheels with many grooves parallel to the wheel’s axis and having a through-hole design (from end to end) maintain their cutting ability over time much better than high-porosity wheels. Therefore, replacing these wheels with high-porosity ones is counterproductive. To ensure the required quality of the surface layer of the machined parts in flat grinding operations, interrupted abrasive wheels with a reduced scale of discretization of the working surface were developed.