The paper presents the results of investigation of pulse atomizing air jet application in electric arc metallizing. To ensure the pulsed mode, the respective device was developed allowing control of outflowing of a jet with frequency within 0-130 Hz. Oscillograms of variation of dynamic pressure are given. Dependence of pulse atomizing air jet on frequency of closing the spray gun nozzle channel is shown. Coating microstructures are given. Influence of pulsation frequency on composition of coatings spray-deposited with PP-MM-2 wire is shown. Electric arc metallizing is one of the methods of deposition of thermal spray coatings and features high efficiency, and quite cost-effective and readily realized process of coating spray-deposition. It is known that during metallizing process liquid metal of molten electrode tips is directed by the atomizing air jet onto the item [1,2]. Quality of produced coatings depends on the quantity of oxygen, dissolved in particle metal. Data given in [3][4][5][6][7][8] show that during metallizing an intensive chemical interaction of atomizing air jet with the material being sprayed takes place, leading to a considerable burning out of alloying elements. Oxidation intensity increases with increase of parameters, such as compressed air pressure and distance from apparatus nozzle to item being coated, that has a negative influence on coating mechanical properties. Degree of oxidizing reaction depends on spray material oxidation resistance, particle dispersity, component affinity to oxygen. Quantitative evaluation of the degree of oxidation of the components of spray electrode material is given in [5][6][7].In order to lower the oxidizing action of atomizing jet on liquid metal of consumable electrode tips, it is proposed to apply a pulse atomizing air jet. To solve the defined task, it was necessary to develop an appropriate device.Earlier publications [9][10][11][12] gave examples of improvement of arc spray gun design by application of inserts and devices to provide pulsation of atomizing air jet. They, however, turned out to be unacceptable in view of their complicated design and inertia in operation.The Chair of Welding Production Equipment and Technology of Priazovsky State Technical University developed the method of electric arc metallizing with application of pulse atomizing air jet. Investigations were conducted with stationary arc spray gun EM-17 with a device providing pulsed mode of atomizing jet outflow.In terms of design, the pulse device (further on referred to as pulser) is a cylindrical case with input and output nipples for compressed air input and output, inside which a shaft with an opening
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