Study of the Additive Products of Electroerosive Cobalt-Chrome Powders by X-Ray Methods

Abstract

This paper presents the results of X-ray methods for studying additive products obtained from electroerosive cobalt-chrome powders. It is experimentally established that the conditions for the preparation and dispersion of the powders determine their behavior during sintering. With an increase in the dispersion of the powder, the sintering process accelerates and proceeds more actively, while the mechanical properties of the resulting products increase. Intensification of sintering of the powder is facilitated by oxides contained in large quantities in fine powders and restored when they are heated during sintering. The spongy metal surface formed after disappearance of the oxide is more active than the surface initially free of an oxide film. As the studies show, the structural phase state of the samples does not change and the presence of the following phases remains constant in all four samples: Co, Cr, Ni, and Cr3Ni2. As the dispersion and specific surface area of the powder increase, its penetration increases and porosity decreases, meanwhile its microhardness increases. The presence of powder particles of different fractions increases the density of its shrinkage due to the filling of troughs and micropores at the joints of large particles, which further leads to a decrease in the roughness of sintered products and an increase in the compressive and bending strength. The conducted studies will solve the problem of the import substitution of powder materials suitable for additive products, and reduce the cost of producing the final product.