INVESTIGATION OF DISPERSION OF DISSIMILAR WIRE MATERIALS DURING ELECTRIC ARC SPRAYING

摘要

The process of combined spraying of steel and copper wires under the electric arc spraying conditions was investigated. The effect of spraying parameters on the process of spraying of dissimilar wires was established, this making it possible to control particle size distribution of the spraying products in electric arc spraying of pseudo-alloy coatings and, hence, structure and properties of the resulting coatings. 2 mm diameter wires, i.e. copper wire of the Ml grade and steel wire Sv-08A, were used as spraying consumables. Investigations were carried out by using electric arc metalliser EM-14M. The regression equations describing dependence of the mean size of particles on the electric power, compressed air pressure and spraying distance were derived by using mathematical experimental design. It was found that the mean size of particles depends primarily on the compressed air pressure. Combining the maximal values of the power (9.6 kW) and compressed air pressure (7 atm) during spraying results in formation of particles of the minimal size: 37μm in spraying of copper wire, 54μm in spraying of steel wire Sv-08A, and 52μm in their combined spraying. Combining the minimal values of the power (1. 7 kW) and compressed air pressure (6 atm) leads to formation of particles of the maximal size: 54μm in spraying of copper wire, 85μm in spraying of steel wire Sv-08A, and 85μm in their combined spraying. It was found that the pseudo-alloy particles consisting of particles of the steel melt with a copper shell on their surface are formed during the process of combined spraying of copper and steel wires as a result of inter-phase interaction of their melts.