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

• Published in: The Physics of Metals and Metallography 2014, Vol.115 (4), p.413
• Main Authors: Potekhin, B.A, Ilyushin, V.V, Khristolyubov, A.S, Zhilyakov, A. Yu
• Format: Report
• Language: English
• Subjects: Analysis; Intermetallic compounds; Steel; Tribology
• ISSN: 0031-918X
• DOI: 10.1134/S0031918X14010128

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.sub.6][Cu.sub.3][Ni.sub.2]Co. 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. Keywords: bronze, dendrite, precipitation hardening, intermetallic compound, solid solution, diffusion, coefficient of friction, mechanical properties