Manipulation of thermal and mechanical stability by addition of multiple equiatomic rare-earth elements in Al-TM-RE metallic glasses. (December 2017)

• Record Type: Journal Article
• Authors: Kim, W.; Oh, H.S.; Park, E.S.
• Is Part Of: Intermetallics. Volume 91(2017)
• Page Start: 8
• Page End: 15
• Publication Date: 2017-12
• Subjects: Al-based metallic glass -- Compositional complexity -- Fragile glass -- Thermal stability -- Thermoplastic formability -- Intrinsic ductility; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2017.07.019
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: In the present study, we demonstrate that the addition of multiple equiatomic rare-earth elements (REs) in the order of electronegativity in Al84 Ni10 RE6 (RE = La, Ce, Nd, Gd, Y) metallic glasses (MGs) can result in stabilizing supercooled liquid region and destabilizing shear avalanches via controllably induced compositional complexity. In detail, the addition of multiple equiatomic REs leads to a relatively fragile glass, but interrupts easy crystallization behavior in Al84 Ni10 (LaCeNdGdY)6 MG, which causes a larger supercooled liquid region and higher thermoplastic formability. Furthermore, the increased structural instability reduces cut-off size of self-organized shear avalanches and increases the number of chaotic shear avalanches, which can distribute the applied strain more homogeneously, resulting in enhanced intrinsic ductility. These results provide a guideline on how to design promising Al-based MGs with high thermal stability and improved mechanical stability, which is a key step to developing ductile Al-based bulk metallic glasses through thermoplastic forming process. Graphical abstract: Highlights: Our study proposes how to design Al-TM-RE MG with higher thermal stability and improved ductility. Addition of the multiple equiatomic REs result in a relatively fragile glass, but interrupt easy crystallization behavior. Those results cause unexpected higher thermal stability and higher thermoplastic formability. The increased structural instability in Al84 Ni10 (LaCeNdGdY)6 MGs enhances chaotic shear avalanches. These results provide a key solution for developing ductile Al-based BMGs through thermoplastic forming process.