Repository logo
 

Novel deformation-induced polymorphic crystallization and softening of Al-based amorphous alloys

Accepted version
Peer-reviewed

Change log

Authors

Bi, HW 
Inoue, A 
Han, FF 
Han, Y 
Kong, FL 

Abstract

© 2018 Acta Materialia Inc. Melt-spun amorphous ribbons of Al 90 Y 10 (at.%) (90Al) and Al 84 Y 8.5 Ni 4 Co 2 Pd 1 Fe 0.5 (84Al) are cold-rolled at near to liquid-nitrogen temperature or at room temperature, inducing partial crystallization to nanoscale fcc-Al (α-Al). The crystallization is characterized and contrasted with the distinct sequences of reactions on annealing 90Al and 84Al amorphous alloys. Rolling-induced crystallization leads to softening, opposite to the effect of nanocrystallization induced by annealing. The origins of the hardness changes are analyzed. The rolling induces novel polymorphic crystallization to α-Al with extended solid solubility. This transformation, which occurs equally in 84Al and 90Al, despite the much greater thermal stability of the former, allows the ribbons to retain good bending ductility, and delays the onset of embrittlement on subsequent annealing. Partial crystallization induced by cold-rolling is useful in avoiding the formation of compound phases associated with brittleness, and is a promising process for high-solute Al-based amorphous alloys to be further developed as structural materials.

Description

Keywords

Amorphous alloy, Crystallization, Hardness, AP-FIM, HRTEM

Journal Title

Acta Materialia

Conference Name

Journal ISSN

1359-6454
1873-2453

Volume Title

147

Publisher

Elsevier BV
Sponsorship
European Research Council (695487)