Observation of a metastable aluminide ThFe2Al10

• Published in: Intermetallics Vol. 36; pp. 133 - 137
• Main Authors: Ganigar, T., Venkert, A., Talianker, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-05-2013
• Subjects: A. Aluminides; A. Intermetallics; Aluminides; Aluminum base alloys; Annealing; Austenitic stainless steels; B. Crystallography; Crystallization; Diffraction patterns; F. Diffraction; F. Electron microscopy, transmission; Intermetallics; Symmetry; Unit cell; F. Electron microscopy, transmission; A. Aluminides; A. Intermetallics; F. Diffraction; B. Crystallography
• ISSN: 0966-9795; 1879-0216
• DOI: 10.1016/j.intermet.2012.09.004

Metastable ThFe2Al10 ternary aluminide was observed in the as-cast Al-6.1at.%Th-6.1at.%Fe alloy. It crystallizes into an orthorhombic structure belonging to Pmmn space group symmetry and possesses unit cell with parameters a = 9.076 Å, b = 8.998 Å and c = 5.031 Å.
The ThFe2Al10 (Pmmn) phase can be considered as a metastable state of the equilibrium ThFe2Al10 (Cmcm) compound; its formation should be directly related to the cooling rate of the alloy during casting. After annealing the as-cast alloy at 600 °C for one week the metastable ThFe2Al10 (Pmmn) phase decomposes: the particles of this phase are no longer observed in SEM, and the diffraction peaks associated with this phase disappear in the XRD pattern.
► A metastable ThFe2Al10 phase was observed in as-cast Al-6.1at.%Th-6.1at.%Fe alloy. ► The metastable ThFe2Al10 aluminide is orthorhombic, belongs to Pmmn space group. ► Its unit cell parameters are a = 9.076 Å, b = 8.998 Å and c = 5.031 Å. ► The ThFe2Al10 (Pmmn) phase is as a metastable state of ThFe2Al10 (Cmcm) phase.