Stabilisation of Ce-Cu-Fe amorphous alloys by addition of Al. Issue 30 (22nd October 2016)

• Record Type: Journal Article
• Authors: Kelhar, Luka; Ferčič, Jana; Boulet, Pascal; Maček-Kržmanc, Marjeta; Šturm, Sašo; Lamut, Martin; Markoli, Boštjan; Kobe, Spomenka; Dubois, Jean-Marie
• Is Part Of: Philosophical magazine. Volume 96:Issue 30(2016)
• Page Start: 3143
• Page End: 3158
• Publication Date: 2016-10-22
• Subjects: Metallic glasses -- rare-earths -- sintering -- stability -- crystallisation; Condensed matter -- Periodicals; Physics -- Periodicals; Matière condensée -- Périodiques; Physique -- Périodiques; 530.41
• DOI: 10.1080/14786435.2016.1229062
• Languages: English
• ISSNs: 1478-6435

Abstract

Abstract: The present work describes the formation of amorphous alloys in the (Al1− x Ce x )62 Cu25 Fe13 quaternary system (0 ≤ x ≤ 1). When the amount of Ce falls in the range 0.67 ≤ x ≤ 0.83, the alloys obtained exhibit a completely amorphous structure confirmed by powder X-ray diffraction. Otherwise, at compositions x = 0.5, 0.58, 0.92 and 1, a primary crystalline phase forms together with an amorphous matrix. The crystallisation temperature ( T x ) decreases with increasing Ce content, varying from 593 K for x = 0.5–383 K for x = 1. Composition x = 0.75 is considered as the best glass former, exhibiting a large supercooled liquid region of 40 K width that precedes crystallisation. In order to form bulk amorphous alloys, ribbons with this later composition were consolidated into few millimetre thick discs using pulsed electric current sintering at different temperatures, yet preserving the amorphous structure. Meanwhile, increasing temperature above 483 K triggers crystallisation of a primary phase isostructural to AlCe3 . Further increase in the temperature up to 573 K yields a higher fraction of the crystalline phase. Testing mechanical properties, using nanoindentation, revealed that both elastic modulus ( E ) and hardness ( H ) depend on the Al content, ranging from E = 85.6 ± 3.7 GPa and H = 6.2 ± 0.7 GPa for x = 0.5 down to E = 39.8 ± 1.0 GPa and H = 3.1 ± 0.2 GPa for x = 0.92.