Environmentally Friendly Technological System of Cutting Using Magnetic Microcapsules and Cutting Tools with Nanoscale Composite Coating

摘要

This work presents the results of theoretical and experimental investigation into machining of various materials without the use of conventional environmental unfriendly cutting fluids while maintaining keys technological performance parameters of machining. In this work, the machining zone was fed with small doses of cutting fluid enclosed in microcapsules. The microcapsules were about 0.8 to 30 μm in size and were made of shell impermeable to the cutting fluid. This study employed microcapsules of increased efficacy, which was achieved by introducing in the capsules, magneto-sensitive compound (Fe 3 O 4 ) with particles size of ≈ 10 nm. Investigation into the effectiveness of machining processes was undertaken using micro-capsules and nano-scale composite coating along with carbide and HSS tools with and without nano-scale composite coatings. The cutting performance of the nano-scale composite coating was investigated with associated environmental impact. It was shown that the direction of motion of the nano-scale composite coating in the liquid carrier in the immediate cutting zone was along the lines of magnetic field, with maximum concentration at the tool tip. It was revealed that, taking into account the dominating magnetic field force (50-120 times) with respect to gravity in nano-scale composite coating, the penetration ability nano-scale composite coating into of contact areas of cutting tools increased sharply compared with the specified index of standard cutting fluid. A comparison of the effectiveness of different cutting processes was carried out in dry cutting, in wet cutting using standard fluid and with the application of nano-scale composite coating with a concentration in the aqueous medium from 1.0 to 4.0%. Turning, drilling and milling operations were undertaken using coated and uncoated tools made of HSS and tungsten carbide. The evaluation of this new technology of nano-scale composite coating as a cutting fluid medium showed that the efficiency of machining using nano-scale composite coating was as good as the cutting process with the standard fluids. In addition, it was observed that using nano-structured multilayer coatings led to higher efficiency exceeding the effectiveness of machining with standard commercial cutting fluids.