Transformation of the quasicrystalline phase Al-Cr-Fe induced by rapid solidification

• Published in: Journal of materials science Vol. 30; no. 11; pp. 2921 - 2929
• Main Authors: ZIANI, A, MICHOT, G, PIANELLI, A, REDJAÏMIA, A, ZAHRA, C. Y, ZAHRA, A. M
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.06.1995
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Metals. Metallurgy; Physics; Quasicrystals; Semi-periodic solids; Structure of solids and liquids; crystallography; Annealing; Aluminium base alloys; Phase transformations; Ternary alloys; Iron alloys; XRD; Chromium alloys; Experimental study; Quasicrystals; Icosahedral phase; DSC; Rapid solidification; Chemical composition; SEM; Microstructure; TEM
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/bf00349664

A quasicrystalline phase, Q, with icosahedral symmetry was detected by x-ray diffraction and transmission electron microscopy in Al-3Cr-xFe (x=0, 1 or 3 at.%) alloys elaborated by hot extrusion of rapidly solidified powders. Chemical microanalysis showed the average composition of this phase to be 75plus /minus0.5% Al, 12plus/minus1% Cr, 12plus/minus1% Fe. Annealing treatments led to its transformation into the equilibrium phases Al sub 13 Cr sub 2 and Al sub 13 Fe sub 4 , directly at high temperature, or through a metastable and unknown phase, X, at intermediate temperature. This transformation was followed by X-ray diffraction, calorimetry and in situ electron microscopy. The convergent-beam technique was used for characterization of the X phase.