Microstructure of some quenched Zr–Cu-based alloys

Abstract

Microstructures of some quenched Zr–Cu-based alloys have been investigated. The scanning electron microscopy (SEM) backscattered electron (BEI) mode was adopted to generate microstructures chemical maps. Every alloy demonstrates dominant eutectic structures with peculiar grain shapes notably heart-like, leaf-like, eutectic-dendrites, which were observed along with the Zr-rich dendrites and the A-shaped Al-rich phases. Other morphologies, for instance, acicular ones have also been observed in the various microstructures that are dependent of the alloys composition and casting conditions. The overall observed microstructures suggest eutectic and peritectic transitions with further solid-state transformation. Furthermore, the crystalline phases in the microstructure involve each alloying element in a complex phases mixture. All the compositions involved in this study yield bulk glassy materials (BMG) under adequate cooling conditions. Thus the various as-described microstructures suggest a multiphase structure in terms of chemical clustering for amorphous structure rather than a single homogeneous phase.