Features of formation of the Al-Cu single crystals structure under the action of pressure and gravitational field on the crystallization process

TL;DR

This study investigates how pressure and gravitational fields influence the structure and composition of Al-Cu single crystals during crystallization, revealing non-uniform element distribution and phase variation.

Contribution

It provides new insights into the effects of external forces on crystal growth and element distribution in Al-Cu alloys during solidification.

Findings

Copper distribution varies with pressure and position in the crystal.

Gravitational field influences eutectic phase concentration.

Non-uniform copper distribution observed in the crystal cross-section.

Abstract

X-ray structural and spectral analyses, X-ray diffraction topography and metallography were used to study dendrite structure of Al-4 wt % Cu single crystals grown by the Bridgman technique at a rate of 1 mm/min and on seeds with <001> orientation. The single crystals were obtained upon the crystallization of the melt under the action of a pressure and the gravitational-field component directed along the surface of the crystallization front. Non-uniform distribution of copper in the solid solution and the eutectic content has been found in transverse section of single crystals and strong increase in their concentration was observed at the lateral side of the samples in the direction of the gravitational-field component action. Distribution of copper and the eutectic phase depend on pressure.