Zr and Mo macrosegregation in Ti6246 titanium alloy industrial-scale ingot by vacuum arc remelting

TL;DR

This study investigates macrosegregation of Zr and Mo in a large Ti6246 titanium alloy ingot during vacuum arc remelting, revealing the influence of solidification dynamics on element distribution.

Contribution

It provides new insights into the formation mechanisms of Zr and Mo macrosegregations during industrial-scale ingot solidification.

Findings

Zr shows low content in equiaxed grains and high in hot top zones.

Mo exhibits an opposite segregation trend to Zr.

Temperature gradient and solidification rate control macrosegregation formation.

Abstract

Zr and Mo macrosegregations were investigated in Ti6246 titanium alloy industrial-scale ingotby vacuum arc remelting. The formation mechanism of Zr and Mo macrosegregations was studied during the solidification process. Zr macrosegregation was characterized by low content in the equiaxed grain zone and high content in the hot top zone. Mo exhibits an opposite trend with Zr. The macrosegregations of Zr and Mo were the most pronounced, with a statistic segregation degree higher than Al and Sn. It could be concluded that temperature gradient and solidification rate dominated the macrosegregation formations during the solidification process. The thermal buoyancy made the negative segregation Zr be continuously discharged to the front of the solid-liquid interface. Mo was enriched in the solid phase at the solid-liquid interface as the positive segregation.