Work

Mushy-zone microstructure and concentration variation of Co-93wt.%Sb hyperperitectic alloy under TGZM effect

Year: 2019

Type: article

Abstract: Skutterudite thermoelectric material, CoSb3 is a peritectic compound, and the traditional preparation method needs several days to obtain single-phase CoSb3 by annealing treatment. In this work, we employed temperature gradient zone melting (TGZM) to investigate the microstructure evolution of Co-93wt.%Sb alloy in mushy zone under different thermal stabilization time. Due to the existence of temperature gradient, two mushy zones between complete liquid phase region and solid phase region were observed. There exists a solute gradient across the mushy zone and the solute diffuses from the cold side to the hot side, inducing that the liquid droplet migrates up the temperature gradient. As the thermal stabilization time increases, the volume fraction of the liquid in mushy zone decreases, and the initial solid/liquid interface moves downwards paralleling to the temperature gradient. After 4h thermal stabilization time, the solute concentration is higher in liquid zone than the nominal alloy concentration, and lower in the mushy zone measured by Energy Dispersive Spectroscopy (EDS). By means of TGZM effect, the preparation time for the CoSb3 thermoelectric materials was shortened remarkably.

Source: Procedia Manufacturing

DOI: 10.1016/j.promfg.2019.12.007

Authors: Xuguang Li, Shuangming Li, Li Dou, Wang Hongqiang, Chang Xueqing

Institutions: Northwestern Polytechnical University, State Key Laboratory of Solidification Processing

Language: English

Topic: Solidification and crystal growth phenomena

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: diamond

Funders: National Natural Science Foundation of China, State Key Laboratory of Solidification Processing

Awards: G5422722559, G8430117423