INVESTIGATION OF THE DRAG FORCES FROM THE SIDE OF THE POWDER ENVIRONMENT ON THE PARTS MOVEMENT DURING THE MAGNETO-ABRASIVE FINISHING IN THE ANNULAR BATH

Abstract

The influence of the technological parameters of the magneto-abrasive finishing (MAF) process on the drag forces to the parts movement of different sizes and shapes, made of ferro- and paramagnetic materials, which act from the side of the ferro-abrasive powder medium formed from various powders in the magneto-abrasive tool (MAT) was investigated. The features of the interaction of the structural elements of the MAT with the surfaces being finished are determined. The influence of the magnetic field strength on the drag forces of the movement of the parts of different sizes and shapes in the MAT was established. It was shown that the process of interaction of MAT with the surfaces of samples being finished with characteristic dimensions up to 12 mm in the annular bath with a width of 35 mm occurs in the "free flow around" mode, while the MAF of samples with characteristic dimensions larger than 12 mm occurs in the "flow around" and "jamming" mode of representative volumes of the MAT between the pole tips and the surface being finished – in the zone of the formed little moving dead zone.
 With the increase in the size of the MAT particles from 200/100 μm to 400/315 μm, the relative value by which the drag forces increase is 1.25–1.65, which is explained by the greater magnetization of larger powders and their formations in the composition of the MAT and, accordingly its greater rigidity.