CALCULATION OF SURFACE ROUGHNESS PARAMETERS AT ABRASIVE TREATMENT

Abstract

New analytical relationships are given that determine the altitude parameters of surface roughness during abrasive machining, taking into account the wear of cutting grains. It is shown that the greater the length of the wear area on the cutting grain (simulating the geometric shape of the cutting part of the grain), the lower the surface roughness parameters Rmax, Ra and the greater the ratio Rmax/Ra, which can increase to values ​​of 30 or more. This is consistent with the known experimental data obtained by abrasive polishing, characterized in fact by a single-height arrangement of abrasive grains on the working surface of the tool. It has been established that for large values ​​of the Rmax/Ra ratio, a tendency is observed in the transition of the cutting process to friction and elasto-plastic deformation of the processed material. When grinding due to the uneven location of the abrasive grains on the working surface of the grinding wheel, the ratio Rmax/Ra is less and varies, as established experimentally, within 4 ... 10. Therefore, grinding operations should be used in the finishing operations with the cutting heads protruding almost at the same height above the level of the bond. This will reduce the height of the microroughness on the machined surfaces.