Composition, Structure and Properties of Antifriction Alloys Based on the Charge Obtained by Electrodispersion of Bronze Waste BrO5C25 in Kerosene

Abstract

Purpose. Study of the composition, structure and properties of antifriction alloys based on the electroerosion charge of bronze BrO5C25 obtained in a carbon–containing medium lighting kerosene.Methods. Dispersion of the waste of the BrO5S25 alloy was carried out at an installation for electrodispersing electrically conductive materials. The waste of the BrO5C25 alloy was used as metal waste. Lighting kerosene was used as the working fluid.As a result of exposure to short-term electrical discharges between the electrodes and the waste, their destruction occurred with the formation of fine particles. To obtain compacted materials, a Herzog TP 20 manual table press was used. Modern equipment and complementary methods of physical materials science were used to study the composition, structure and properties of the sintered products obtained.Results. Surface analysis showed that the alloys have a fine-grained structure, uniform phase distribution and a small number of pores. The analysis of the elemental composition found that carbon is contained on the surface of the new alloys, and all other elements Sn, Cu and Pb are distributed relatively evenly. The analysis of the studied alloys showed the presence of phases in them: Cu, CuSn, SnO, CuO, PbO, Pb. There are no carbide-forming elements in the alloy. It has been experimentally established that the composition, structure and properties of the charge dispersed by electroerosion of bronze BrO5C25 affect the tribological properties of the alloy blanks. In particular, the presence of free carbon in the alloy from the electroerosion charge obtained in kerosene, which acts as a solid lubricant, leads to a decrease in the coefficient of friction.Conclusion. It is shown that alloys obtained from an electroerosive charge have higher microhardness values in comparison with an alloy obtained from an industrially used charge. A significant increase in the microhardness of alloys is explained by the presence of highly hard particles formed during the quenching of metal vapors in the working fluid during dispersion. The presence of small fractions in electroerosive materials contributes to an increase in the density of compressions and a decrease in the porosity of workpieces.