Магнитно-абразивная обработка плоских поверхностей головками на постоянных магнитах

Abstract

The paper investigates the features of magnetic abrasive machining of flat surfaces of ferromagnetic parts by end magnetic heads, which are made from high-power permanent neodymium magnets. The distribution of the magnetic field near the working surface of the magnetic heads kind of brush and half of torus was studied. The cycle of studies was carried out on the influence of the shape of the working surfaces of magnetic heads in the shapes of an annular protrusion on the periphery of the head, with radial beam protrusion and a group of radially arranged pyramidal protrusions with high of 2-3 mm on the roughness of flat ferromagnetic parts provided as a result of magneto-abrasive machining. The possibility of obtaining a surface roughness with Ra < 0.05 μm at the initial roughness at the level of Ra = 1–1.25 μm as a result of magnetic abrasive machining with end magnetic heads is shown. It was determined that an effective process of magnetic abrasive machining is realized when the ratio of the change in roughness achieved during machining to the initial roughness exceeds value 0.85. The influence of the value of the working gap, the height of the magnetic abrasive tool, which is shaped on the working plane of the head, and the magnitude of the magnetic induction in the working zones on the efficiency of the process is analyzed. The use of brush-type magnetic heads is recommended, in which protrusions in the form of a group of pyramids 2–3 mm high are formed on the working end surfaces. For heads of this type, the machining efficiency corresponds to a value of 0.89–0.91.