Abstract Scope |
Copper-manganese alloys based on the congruent minimum at 34.6 wt% Mn have high castability due to the vanishingly narrow freezing range, resulting in cellular (non-dendritic) solidification under conventional casting. Alloys with the near-congruent Cu:Mn ratio were produced using blends of electrolytic Mn (99.9%) and standard ferro-manganese (78% Mn, balance Fe, C), bringing in additional Fe and C. Microstructure analysis revealed a potent effect of grain nucleation due to the high-melting Fe, and mixtures of carbon-containing phases, depending on the oxidizing conditions in air melting. Microstructure development is analyzed in terms of the available ternary and quaternary phase relations. |