Structural Characterization of Al65Cu20Fe15 Melt-Spun Alloy by X-ray, Neutron Diffraction, High-Resolution Electron Microscopy and Mössbauer Spectroscopy.

Rafał Babilas,Dariusz Łukowiec,Tomasz Czeppe,Wojciech Łoński,Mariola Kądziołka-Gaweł,László Temleitner,Katarzyna Młynarek

doi:10.3390/ma14010054

Abstract

The aim of the work was to characterize the structure of Al65Cu20Fe15 alloy obtained with the use of conventional casting and rapid solidification-melt-spinning technology. Based on the literature data, the possibility of an icosahedral quasicrystalline phase forming in the Al-Cu-Fe was verified. Structure analysis was performed based on the results of X-ray diffraction, neutron diffraction, 57Fe Mössbauer and transmission electron microscopy. Studies using differential scanning calorimetry were carried out to describe the crystallization mechanism. Additionally, electrochemical tests were performed in order to characterize the influence of the structure and cooling rate on the corrosion resistance. On the basis of the structural studies, the formation of a metastable icosahedral phase and partial amorphous state of ribbon structure were demonstrated. The possibility of the formation of icosahedral quasicrystalline phase I-AlCuFe together with the crystalline phases was indicated by X-ray diffraction (XRD), neutron diffraction (ND) patterns, Mössbauer spectroscopy, high-resolution transmission electron microscopy (HRTEM) observations and differential scanning calorimetry (DSC) curves. The beneficial effect of the application of rapid solidification on the corrosive properties was also confirmed.

Highlights

The technologies of rapid solidification (RS), such as melt-spinning, water quenching, arc-melting, high pressure die casting, allow one to obtain a wide range of unique structures of aluminum alloys [1,2,3]
Structure analysis was performed based on the results of X-ray diffraction, neutron diffraction, and 57 Fe Mössbauer in order to perform a phase composition analysis and confirm the occurrence of individual phases in all research techniques used
Main diffraction peaks of the ingot alloy can be identified as the AlCuFe icosahedral phase [18], and the other diffraction peaks correspond to multiple phases of Al2 Cu, Al7 Cu2 Fe, AlFe, Al13 Fe4 and Cu3 Al (Figure 1a)

Summary

Introduction

The technologies of rapid solidification (RS), such as melt-spinning, water quenching, arc-melting, high pressure die casting, allow one to obtain a wide range of unique structures of aluminum alloys [1,2,3]. It is possible to fabricate Al-based alloys with structures such as: amorphous single phase, partially crystallized particles in an amorphous matrix, quasicrystals in Al matrix without grain boundary, and granular amorphous phases of aluminum with or without surrounding amorphous phase [2,4]. It seems interesting to obtain quasicrystalline structures, which constitute the third state of a solid state next to crystalline and amorphous states [5]. Many alloying systems in which it is possible to obtain quasicrystalline phases were described in the literature, which proves their common occurrence. Metastable icosahedral phase systems are: Al-TM(V, Cr, Mn, Ru, Re) [9], Al-(Mn, Cr, Fe)-(Si, Ge) [9,10], Al-(Cu, Pd)-TM(Cr, Mn, Fe, Mo, Ru, Re, Os) [5,9,11]

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