Microstructural evolution of the η-phase in the Cu–Sn system

Abstract

The formation of η-phase by a peritectic reaction in the Cu–Sn metallic system has been cited in the literature while discussing the solidification of the high temperature superconductor Yba2Cu3O7 through the peritectic temperature, from Y2BaCuO5 and liquid phases. Similar schematic phase diagrams and driving forces have been invoked to discuss the reactions in both cases. In this paper, we have studied the microstructural evolution of the η-phase from є + liquid in the Cu–Sn system, by observing quenched microstructures at various stages of processing, when subjected to a thermal schedule similar to the one used for the melt-processing of YBa2Cu3O7. A comprehensive picture of the mechanism by which the η phase nucleates and grows has evolved.