Investigation of the intermetallic phase stabilities and phase equilibria in Cu-Co-Sm system. Part 1: Cu-Sm system

The binary Cu-Sm system is one of the basic sub-systems, necessary for the development of the materials used as permanent magnets. Nonetheless, there can be found numerous inconsistencies in the phase equilibria data for the system. The current work deals with the evaluation of the phase stabilities of the intermetallic phases in the system and phase equilibria in the Cu-Sm system with the DTA, SEM/EPMA and XRD methods. Cu6Sm and Cu5Sm have been found to express some homogeneity ranges. It was confirmed that CuSm is forming by a peritectic reaction, rather than by congruent melting. The updated phase equilibria data was summed up in a new version of the Cu-Sm phase diagram. The hardness of the Cu6Sm phase was found to be 335 +/- 29 HV. (c) 2023 Elsevier B.V. All rights reserved.