XRD and HREM studies from the decomposition of icosahedral AlCuFe single-phase by high-energy ball milling

• Published in: Journal of alloys and compounds Vol. 509; no. 41; pp. 10036 - 10039
• Main Authors: Patiño-Carachure, C., Téllez-Vázquez, O., Rosas, G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 13.10.2011; Elsevier
• Subjects: Alloys; Ball milling; Condensed matter: structure, mechanical and thermal properties; Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Heat treatment; Icosahedral phase; Materials science; Materials synthesis; materials processing; Mechanical alloying; Nanomaterials; Nanostructure; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase stability; Physics; Quasicrystals; Reduction; Semi-periodic solids; Structure of solids and liquids; crystallography; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermodynamic properties; Transmission electron microscopy (TEM); X-ray diffraction; X-ray diffraction; Quasicrystals; Mechanical alloying; Transmission electron microscopy (TEM); High resolution electron microscopy; Cubic lattices; Fivefold symmetry; Beta phase; Deformation; Ball mill; Phase transformations; XRD; Powder metallurgy; Heat treatments; Induction furnaces; Icosahedral phase; Casting; Transmission electron microscopy; Phase stability; Powder grinding; Thermodynamic properties; Melts
• DOI: 10.1016/j.jallcom.2011.08.026
• ISSN: 0925-8388

► Point defects induced during milling leading to an order–disorder quasicrystal transition. ► Nanoquasicrystalline regions of 12 nm are obtained. ► Highly ordered i-phase with high symmetry transforms to a crystalline phase of intermetallic character and lower symmetry. In this investigation the Al 64Cu 24Fe 12 alloy was melted in an induction furnace and solidified under normal casting conditions. In order to obtain the icosahedral phase (i-phase) in a single-phase region, the as-cast sample was subject to a heat treatment at 700 °C under argon atmosphere. Subsequently, the i-phase was milled for different times in order to evaluate phase stability under heavy deformation. X-ray diffraction (XRD) and high-resolution electron microscopy (HREM) analysis were conducted to the structural characterization of ball-milled powders. XRD results indicated a reduction in quasicrystal size during mechanical ball milling to about 30 h. HREM analysis revealed the presence of aperiodic nano-domains, for example, with apparent fivefold symmetry axis. Therefore, the i-phase remains stable over the first 30 h of ball-milling time. However, among 30–50 h of mechanical milling the i-phase transforms progressively into β-cubic phase.