Timoshenko V. Improvement of abrasive diamond grinding powders of AC6–AC20 grades by the directed change of their sizes and physical-mechanical characteristics

The actual scientific and technical problem of production of abrasive diamond grinding powders of AC6–AC20 grades synthesized using Fe-Si and Ni-Mn alloys has been solved in the work. The diamond grinding powders, which differ in magnetic properties through the difference in the amount of entrained solvent metal (from 1×10-4 to 1×10-8 m3/kg) and abrasive ability (from 1 to 3 mg) were produced due to the effect of physical-mechanical processing of diamond grains and magnetic sorting of the grains into a number of factions (in the magnetic field with a strength from 5 to 20 Е). These powders are intended for manufacturing of grinding tool of the increased wear resistance. It was found that the removal – by thermochemical treatment in an alkaline solution – of sharp edges of grains of the initial AC6 diamond powders of non-magnetic fractions of narrow 100/90 grain size synthesized in the Ni-Mn-C system provides growth of the developed surface by at least 30 % (Ka increases from 0.45 to 0.65 %). This, in turn, provides better retention of diamond grains in the binder and leads to a decrease the relative consumption of diamond grains (~ by 20%) during grinding with the wheels with metal-polymer bond of B2-01-1 grade. As a result of the performed researches the experimental-industrial technology of production of grinding powders of special purpose of AC6–AC20 grades of 160/125–63/50 grain sizes – with high uniformity in strength and in linear sizes and with different content of intracrystalline impurities and inclusions – which are differed in the value of the specific magnetic susceptibility and abrasive ability has been developed. The technology has been experimentally tested at the state company “ALCON-DIAMANT”.