Liquid structure changes of Bi under different melt states

TL;DR

This study investigates how the liquid structure of bismuth (Bi) changes with different melt states and how these changes influence solidification behavior, revealing a liquid-liquid transition that affects metallicity and solidification characteristics.

Contribution

It identifies a liquid-liquid structure transition in pure Bi melt and explores its impact on solidification behavior and microstructure.

Findings

Liquid-liquid transition occurs at 744°C in pure Bi.

Solidification microstructure varies significantly with melt state.

Transition increases metallicity and alters solid-liquid interface morphology.

Abstract

This paper is focused on the relationship between solidification and melt sates. An abnormal change which takes place at 744 C from 84 to 120 min indicated a liquid-liquid structure transition in pure Bi melt. Based on liquid-liquid structure transition, experiments of pure Bi were carried out. Cooling from different melt states, the solidification behaviors and structures changed a lot, such as undercooling, solidification time, grain sizes and the number of twins and pedestal sits. Especially, as a semi-metal, a liquid-liquid structure transition greatly increases the metallicity of Bi, and during the solidification Bi turned from smooth to coarse solid/ liquid interface.