Formation and stability of icosahedral phase in Al65Ga5Pd17Mn13 alloy

TL;DR

This study reports the formation and characterization of a novel icosahedral quasicrystal in Al-Ga-Pd-Mn alloy, highlighting its structural phases and the conditions needed for its stability.

Contribution

First demonstration of icosahedral phase formation in Al-Ga-Pd-Mn alloy using specific annealing techniques.

Findings

Confirmed icosahedral and orthorhombic phases via X-ray and TEM.

Observed pseudo twelve fold pattern in as cast alloy.

Identified Ga presence in the alloy.

Abstract

In this work, we present the formation and characterization of a quaternary (pseudo ternary) icosahedral quasicrystal in Al65Ga5Pd17Mn13 alloy. The X ray diffraction and transmission electron microscopy confirmed the formation of icosahedral B2 type and O crystalline (orthorhombic structure) phases in as cast alloy. The icosahedral phase gets formed after annealing at 800 C for 60 hours. The formation of icosahedral phase in AlGaPdMn quaternary alloy by present technique has been studied for the first time. The Energy dispersive X-ray analysis investigations suggest the presence of Ga (5 at) in the alloy. It is interesting to note that pseudo twelve fold pattern in the as cast alloy has been observed. Icosahedral AlGaPdMn provides a new opportunity to investigate the various characteristics including surface characteristics. Attempts will be made to discuss the micromechanisms for the formation of quasicrystalline phase in Al-Ga-Pd-Mn alloys.