Nanocrystal development during primary crystallization of amorphous alloys

Allen, Douglas; Foley, Jim; Perepezko, John H.

doi:10.1016/s1359-6454(97)00279-6

Cited by 235 publications

(138 citation statements)

References 29 publications

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“…Al-rich metallic glasses, containing transition metal (TM) and rare earth (RE) elements have attracted considerable attentions due to the occurrence of primary crystallization reaction that yields a microstructure with Al nanocrystals dispersion-embedded in an amorphous matrix, which can deserve excellent mechanical properties [1][2][3][4][5]. These excellent mechanical properties make this family of Al-based amorphous alloys promising candidates as advanced engineering materials.…”

Section: Introductionmentioning

confidence: 99%

“…To summarize the DSC, XRD and HREM results, we can conclude that the small addition of Si plays an important role in the crystallization mechanism transformation, from a nucleation and growth control pattern to a growth control pattern. This transformation can deserve microstructures with finely dispersed nanocrystalline Al in an amorphous matrix, excepted excellent mechanical properties like some reported amorphous alloy [3][4][5]. Many researchers have proposed different option on the crystallization process.…”

Section: Introductionmentioning

confidence: 99%

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Nano-Al Formed by Phase Separation in the Al85Ni10Ce5 Metallic Glass

Wang¹

2011

TOMSJ

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A nucleation-growth control for Al 85 Ni 10 Ce 5 glass has transformed to a growth control for Al 83 Ni 10 Ce 5 Si 2 glass. That's to say a small quantity of Si addition can successfully separate the Al phase to single precipitate from a eutectic precipitation composited of Al and other intermetallic compound to synthesize nanostructured materials, characteristic of microstructures with finely dispersed nanoccrystalline Al in an amorphous matrix. Favorably no evident decrease of glass forming ability is observed in the transformation. We suggest that the Si atoms solve into Al lattice to sever as preexist nucleus for fcc-Al, in the same time; a nucleation reaction of fcc-Al is accompanied to compensate the nucleation rate.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nano-Al Formed by Phase Separation in the Al85Ni10Ce5 Metallic Glass

Wang¹

2011

TOMSJ

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“…Al-rich metallic glasses, containing transition metal (TM) and rare earth (RE) elements have attracted considerable attentions due to the occurrence of primary crystallization reaction that yields a microstructure with Al nanocrystals dispersion embedded in an amorphous matrix to deserve excellent mechanical properties [1][2][3][4][5][6][7]. Primary crystallization behavior is empirically related to Al-rich composition ( 87 at.…”

Section: Introductionmentioning

confidence: 99%

“…% Al) [8][9][10]. To understand the origin of crystallization, various competing models have been proposed, such as heterogeneous nucleation [11], the presence of a large density of quenched-in nuclei in the amorphous [2,12], a new kind of homogeneous nucleation mechanism ('linked flux') [13,14] and a phase separation mechanism which indicates nucleation of fcc-Al arises at the interface of the phase separation regions [15]. However, the correct crystallization mechanism has yet to be identified in the Albased metallic glasses.…”

Section: Introductionmentioning

confidence: 99%

Relation Between Medium-Range Order and Crystallization in Al-Ni Based Metallic Glass

Wang¹

2011

TOMSJ

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“…Literatures 4,10,11) report the formation of nano-scale Al-particles from Al-Ni based amorphous alloys. The crystallisation kinetics of fcc-Al in Al-NiCe [10][11][12][13] and Al-Ni-Y [14][15][16][17] amorphous alloys have been intensively investigated. All these alloys contain expensive rare earth materials.…”

Section: Introductionmentioning

confidence: 99%

Crystallization Kinetics in an Amorphous Al-Ni-Mm-Fe Alloy

2003

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Differential scanning calorimeter (DSC) has been used to study the crystallization kinetics of Al 87:5 Ni 7 Mm 5 Fe 0:5 alloy. Both isochronal and isothermal DSC plots showed that the Al 87:5 Ni 7 Mm 5 Fe 0:5 alloy undergoes three stages crystallization process. The first peak corresponds to the precipitation of fcc-Al from the amorphous matrix at around 160 C. Isothermal DSC traces showed that there is a short incubation stage for the formation of nanoscale Al particles. The value of Avrami exponent suggests that the crystallization of Al crystals starts with a nucleation process for a short time and finally controlled by a growth mechanism. The second peak corresponds to the crystallization of Al 11 (La,Ce) 3 from the matrix at around 320 C with a nucleation rate, which decreases with time, and a constant growth rate. The activation energy calculated for the crystallization of Al 11 (La,Ce) 3 phase is 288 AE 5:9 kJ/mol, 324:6 AE 18 kJ/mol, 292 AE 6 kJ/mol by Kissinger, Johnson-Mehl-Avrami and Arrhenius type equations. The difference in the values of kinetic energy is mainly due to different annealing conditions. The third peak at around 340 C corresponds to the precipitation of intermetallic compounds from the remaining matrix.

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Nanocrystal development during primary crystallization of amorphous alloys

Cited by 235 publications

References 29 publications

Nano-Al Formed by Phase Separation in the Al85Ni10Ce5 Metallic Glass

Nano-Al Formed by Phase Separation in the Al85Ni10Ce5 Metallic Glass

Relation Between Medium-Range Order and Crystallization in Al-Ni Based Metallic Glass

Crystallization Kinetics in an Amorphous Al-Ni-Mm-Fe Alloy

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