Formation of structure and properties of composite bronzes reinforced by steel dendrites

Abstract

The investigation of experimental alloys of the BrZhNKA 9-4-1-1 type has shown the possibility of production of bronzes as antifriction alloys, in which, instead of brittle intermetallic compounds, steel dendrite-like inclusions of, e.g., steel N12K7Yu, are used. In these alloys, the phenomenon of the redistribution of alloying elements (Ni, Co, Al) between the matrix and dendrites in the process of heat treatments has been considered. The growth of these dendrites was found to occur in the solid state via the directional diffusion of Fe, Ni, and Co from the copper matrix to dendrites. This leads to the formation of a shell around them, which represents a substitutional solid solution of Cu, Ni, and Co in iron, e.g., with a composition of Fe 6Cu3Ni2Co. On the whole, the mechanical, tribological, and engineering properties of such bronzes, e.g., BrZhNKA 9-4-1-1, are higher than those of the well-known antifriction bronzes BrO10 or BrAZhN 10-4-4. © 2014 Pleiades Publishing, Ltd.