Ball milling-induced nanocrystal formation in aluminum-based metallic glasses

Journal Article · Sun Jan 01 00:00:00 EST 1995 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(95)90264-3· OSTI ID:6549044

He, Y; Shiflet, G J; Poon, S J ^[1]

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1. Univ. of Virginia, Charlottesville, VA (United States)

Various experimental techniques have been used to investigate the effect of mechanical milling on the structural stability of rapidly solidified aluminum-based metallic glasses. Using transmission electron microscopy (TEM) and X-ray diffraction methods, the formation of nanocrystalline Al particles in some ball-milled Al-rich metallic glasses (such as Al[sub 90]Fe[sub 5]Gd[sub 5] and Al[sub 90]Fe[sub 5]Ce[sub 5]) is clearly observed. For other compositions with lower Al concentration such as Al[sub 85]Ni[sub 5]Y[sub 10], no such phase transformation can be detected by TEM or X-ray. However, differential scanning calorimetry (DSC) measurements show that the crystallization peaks of the ball-milled Al[sub 85]Ni[sub 5]Y[sub 10] metallic glass shifted to higher temperature, while the crystallization enthalpy associated with the first exothermic peak decreased to a lower value, revealing that certain structural changes have taken place as a result of mechanical deformation. The compositional dependence of the structural stability of Al-based metallic glasses against mechanical deformation suggests that the nanocrystal formation induced by a deformation process is different from that caused by a thermal process. The large plastic strain induced atomic displacements and the enhancement of atomic mobility during the deformation process, are the possible mechanisms of mechanical deformation-induced crystallization. Their results demonstrate a new way of obtaining nanophase glassy composite alloy powders which are suitable for engineering applications upon further consolidation processing.

• OSTI ID: 6549044
• Journal Information: Acta Metallurgica et Materialia; (United States), Vol. 43:1; ISSN 0956-7151
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
CRYSTALLIZATION
CERIUM ALLOYS
GADOLINIUM ALLOYS
IRON ALLOYS
NICKEL ALLOYS
YTTRIUM ALLOYS
AMORPHOUS STATE
METALLURGICAL EFFECTS
MICROSTRUCTURE
PLASTICITY
STRAINS
ALLOYS
ALUMINIUM ALLOYS
MECHANICAL PROPERTIES
PHASE TRANSFORMATIONS
RARE EARTH ALLOYS
360102* - Metals & Alloys- Structure & Phase Studies