Обработка плоских поверхностей магнитно-абразивным методом торцевыми головками на постоянных магнитах 1. Влияние типа магнитно-абразивного порошка на эффективность магнитно-абразивной обработки

摘要

Background.The modern production requires finishing surfaces of steel parts with zero and small curvature in order to reduce roughness and obtain a smoothed microprofile. Actual is the creation of a mobile, universal movably coordinated abrasive tool, which has a wide range of uses on machines of various types. For this, it is necessary to carry out studies on the influence of not only the type of magneto-abrasive powder, but also its shape and size on the effectiveness of flat surfaces machining by high-power permanent magnet end-type heads, and determine the rational conditions for their exploitation. Objective. The aim of this work was to determine the effectiveness of the magneto-abrasive machining process by permanent magnet end heads of flat ferromagnetic surfaces by the magneto-abrasive powders of various types, with different particle shapes and the size of the working gap. Methods. The study was carried out on flat samples of steel 45 with their preliminary preparation by face milling and grinding. Their machining was carried out by the head, on the working end of which the magneto-abrasive powder is formed in the form of a brush, with the different working gaps. Results. The paper presents the results of studies of magneto-abrasive machining of flat surfaces by the heads with permanent high-power magnets. In the study of the possibility of using magneto-abrasive powders of different types, shapes and sizes, it was shown that it is advisable to use powders with an angular particle shape with a large number of cutting micro edges on the particle surface and with a small radius of their rounding. The obtained results suggest, that the process of formation of the magneto-abrasive tool, directly its shape and the nature of the arrangement of magneto-abrasive particles and their groups relative to the machined surface will have a significant impact on the final result of machining. Conclusions. In the result of experimental studies of the process of magneto-abrasive machining of flat steel surfaces by powders of various types and grit, it was shown that it is possible to provide a surface roughness with Ra ? ? 0.05 ? μm with simultaneous removing surface waviness. It was established that the decisive technological guideline when achieving the minimum roughness is the size of the working gap, which should be at least 1.5 ? mm.