Lowering critical cooling rate for forming bulk metallic glass

Nanoscale dimples and periodic corrugations are observed on the fracture surface of Zr-based bulk metallic glass composite (BMGC). The nanoscale periodic corrugations display a curved shape, which is different from that observed in previous works. In addition, the crystallization behavior of [Formula: see text][Formula: see text][Formula: see text][Formula: see text] BMG was investigated. The second crystallization event of Zr-Cu-Ni-Al BMG can be controlled by annealing or tuning cooling rate. The in situ Zr-based BMGC was prepared via lowering cooling rate. The Zr-based BMGC displays completely brittleness.

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Fabrication of ternary Mg–Cu–Gd bulk metallic glass with high glass-forming ability under air atmosphere

Journal of Materials Research ◽

10.1557/jmr.2003.0207 ◽

2003 ◽

Vol 18 (7) ◽

pp. 1502-1504 ◽

Cited By ~ 130

Author(s):

H. Men ◽

D. H. Kim

Keyword(s):

Metallic Glass ◽

Cooling Rate ◽

Bulk Metallic Glass ◽

Glass Formation ◽

Glass Forming Ability ◽

Casting Method ◽

Glass Forming ◽

Air Atmosphere ◽

Mold Casting ◽

Order Of Magnitude

A new Mg65Cu25Gd10 alloy having significantly improved glass-forming ability (GFA) has been developed. In this article, we show that the ternary Mg65Cu25Gd10 bulk metallic glass with diameter of at least 8 mm can successfully be fabricated by a conventional Cu-mold casting method in air atmosphere. The critical cooling rate for glass formation was estimated on the order of magnitude of approximately 1 K/s. When compared with the GFA of Mg65Cu25Y10 alloy, the significantly improved GFA of Mg65Cu25Gd10 alloy cannot be explained by ΔTx and Trg values.

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Effect of Cooling Rate on Glass Forming Ability of Novel Fe-Based Bulk Metallic Glass

Acta Physica Polonica A ◽

10.12693/aphyspola.138.265 ◽

2020 ◽

Vol 138 (2) ◽

pp. 265-267

Author(s):

H. Redaei ◽

P. Rezaei-Shahreza ◽

A. Seifoddini ◽

S. Hasani

Keyword(s):

Metallic Glass ◽

Cooling Rate ◽

Bulk Metallic Glass ◽

Glass Forming Ability ◽

Glass Forming

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Effect of the cooling rate on plastic deformability of a Zr-based bulk metallic glass

Science China Physics Mechanics and Astronomy ◽

10.1007/s11433-010-0141-y ◽

2010 ◽

Vol 53 (3) ◽

pp. 415-418 ◽

Cited By ~ 11

Author(s):

Jing Zhang ◽

ShuJie Pang ◽

Tao Zhang

Keyword(s):

Metallic Glass ◽

Cooling Rate ◽

Bulk Metallic Glass

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Atomistic Theory of Bulk Metallic Glass Formation

MRS Proceedings ◽

10.1557/proc-754-cc2.5 ◽

2002 ◽

Vol 754 ◽

Author(s):

T. Egami

Keyword(s):

Glass Transition ◽

Metallic Glass ◽

Cooling Rate ◽

Bulk Metallic Glass ◽

Glass Formation ◽

Dynamics Simulation ◽

Necessary Condition ◽

Atomic Transport ◽

Strong Repulsion ◽

First Time

ABSTRACTBulk metallic glass can be formed only when the critical cooling rate for glass formation is reduced to 100–2 K/sec. However, a cooling rate achievable with molecular dynamics simulation is higher by many orders of magnitude, so the gap has to be abridged by analytical theories. We propose a theory of bulk metallic glass formation based upon our early theories of glass formation composition. The critical concepts include the idea of local glass transition, distributed local glass transition temperatures and coincident local fluctuation for atomic transport. Strong repulsion between small atoms was recognized for the first time as the necessary condition for bulk glass formation.

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The Critical Cooling Rate of Fe-Based Mono-Sized Spherical Particles with Fully Glassy Phase

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.509.185 ◽

2012 ◽

Vol 509 ◽

pp. 185-191 ◽

Cited By ~ 5

Author(s):

Ying Li ◽

Wei Dong ◽

Yi Fan Fu ◽

Yi Tan ◽

Ayako Miura ◽

...

Keyword(s):

Metallic Glass ◽

Cooling Rate ◽

Glassy Phase ◽

Particle Diameter ◽

Spherical Particles ◽

Critical Cooling Rate ◽

Alloy Particles ◽

Temperature Transformation ◽

Ejection Method ◽

Glass Alloy

A new method to evaluate the critical cooling rate, Rc of Fe-based metallic glass alloy was proposed and discussed. [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 alloy particles were prepared with narrow size distribution and high sphericity by Pulsated Orifice Ejection Method in Ar, He and 50%Ar+50%He mixed atmosphere, respectively. Phase transition of a particle from amorphous to amorphous-crystalline and fully crystalline occurred with the increase of particle diameter. Rc of the formation of fully amorphous phase was estimated to be in the range of 700-1100 K/s, lower than that measured by time-temperature transformation diagram of bulk metallic alloy. No change of Rc occurred in Ar, He or 50%Ar+50%He mixed atmosphere, which proved it an effective method to evaluate the critical cooling rate of Fe-based metallic glass alloy.

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