Effect of Sb Addition on the Solidification of Deeply Undercooled Ag-28.1 wt. % Cu Eutectic Alloy

Su Zhao,Yunxia Chen,Donglai Wei

doi:10.3390/met6020039

Abstract

Ag-28.1 wt. % Cu eutectic alloy solidifies in the form of eutectic dendrite at undercooling above 76 K. The remelting and ripening of the original lamellar eutectics result in the formation of the anomalous eutectics in the final microstructure. The addition of the third element Sb (0.5 and 1 wt. %) does not change the growth mode, but enlarges the volume fraction of anomalous eutectics because of the increasing recalescence rate. The additional constitutional supercooling owing to the Sb enrichment ahead of the eutectic interface promotes the branching of the interface and as a result fine lamellar eutectic arms form around the anomalous eutectics in the Sb-added Ag-28.1 wt. % Cu eutectic alloy.

Highlights

Binary eutectic alloys usually solidify into regular lamellar eutectics under equilibrium solidification conditions [1,2,3]
The effect of trace Sb addition on the crystal growth mode and the microstructure of Ag-28.1 wt. % Cu eutectic alloy at high undercoolings will be systematically investigated
A temperature decreases to TN (Stage 1), and at this time, nuclei form, and ∆T = TE TN (∆T, undercooling; TE, eutectic temperature)

Summary

Introduction

Binary eutectic alloys usually solidify into regular lamellar (rod) eutectics under equilibrium solidification conditions [1,2,3]. Much attention has been paid to the solidification at high undercooling [9,10,11,12]. As a small amount of third element is added to a binary eutectic alloy, both a transverse and longitudinal diffusions of the added element in the liquid ahead of the solid-liquid interface is established, due to which the growth behavior changes. There have been few experimental investigations on the solidification of eutectic alloys containing a small amount of third element at high undercooling. % Cu eutectic alloy at high undercoolings will be systematically investigated The effect of trace Sb addition on the crystal growth mode and the microstructure of Ag-28.1 wt. % Cu eutectic alloy at high undercoolings will be systematically investigated

Methods

Results

Conclusion