Fragility of iron-based glasses

Na, Jong Hyun; Demetriou, Marios D.; Johnson, William L.

doi:10.1063/1.3651763

Cited by 28 publications

(2 citation statements)

References 21 publications

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“…Na et al [47] studied the fragility of Fe-based glasses, and found that m and glass formability are inversely correlated for Fe-based alloys. This suggests that the amorphous phase in Fe-based alloys is kinetically stabilized.…”

Section: Mechanism Of Grain Refinement By Uramentioning

confidence: 99%

Nano-crystallisation and magnetic softening in Fe–B binary alloys induced by ultra-rapid heating

Parsons¹,

Zang²,

Onodera³

et al. 2018

J. Phys. D: Appl. Phys.

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Magnetically soft nanostructures are known to be prepared by the primary crystallisation of Fe-based amorphous precursors containing Cu and/or Nb. These nonmagnetic additives are essential for accelerated nucleation and retarded crystal growth during crystallisation. However, it has recently been found that none of these additives are necessary for the preparation of similar nanostructures when ultra-rapid annealing (URA) is employed. As a result, a magnetically soft nanostructure with exceptionally high Fe contents is realized in a simple Fe-B binary system. An obvious question is the mechanism of the nanostructural formation in such a simple system. To answer this question, the crystallisation behaviour of amorphous precursors was investigated by means of in situ resistivity measurements with heating rates up to ~100 K s −1 . The primary crystallisation temperature (T p ) in Fe 86 B 14 is increased at least by ~100 K under URA. This brings T p to the vicinity of the glass transition (T g ) predicted by Egami's zeroth-order approximation, suggesting that an enhanced nucleation rate near T g due to the contribution of homogeneous nucleation could be responsible for the nanostructural formation in Fe 86 B 14 . Contrarily, the effect of URA is absent from Fe 80 B 14 Nb 6 , and a magnetically soft nanostructure is realized by conventional annealing because the crystallisation reaction in this alloy takes place above T g even with a low heating rate of ~1 K s −1 . URA offers new possibilities for enhancing the saturation magnetization in nanocrystalline soft magnetic alloys through reductions of the amount of nonmagnetic additives.

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Section: Mechanism Of Grain Refinement By Uramentioning

confidence: 99%

Nano-crystallisation and magnetic softening in Fe–B binary alloys induced by ultra-rapid heating

Parsons¹,

Zang²,

Onodera³

et al. 2018

J. Phys. D: Appl. Phys.

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show abstract

“…Although the small interfacial energy is not beneficial for the GFA, the formation of ISRO is expected to increases the melt viscosity [40,41]. Sluggish atomic movements due to a high viscosity affect the nucleation and growth rate and may lead to an increasing GFA as demonstrated by Na et al for Fe-based bulk glass-forming liquids [42]. The importance of the viscosity for the glass formation in this system is supported by the observation that the viscosity at the liquidus temperature of the Ti 60 Zr 15 Cu 17 S 8 bulk glass-forming alloy composition (same alloy family as Ti 58 Zr 7.5 Ni 18.5 Cu 12 S 4 ) is approximately one order of magnitude higher than that of the Ti 37 Zr 42 Ni 21 liquid [22,30].…”

Section: Discussionmentioning

confidence: 99%

Bulk metallic glass formation in the (Ti,Zr)–(Ni,Cu)–S system

Gross

Ruschel

Kuball

et al. 2020

J. Phys.: Condens. Matter

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New bulk glass-forming alloy compositions, exceeding a critical casting thickness of 1 mm, are developed in the (quasi-ternary) (Ti,Zr)-(Ni,Cu)-S system. The ternary eutectic composition Ti 65.5 Ni 22.5 Cu 12 is stepwise modified through additions of S (0-8 at%) and Zr (0-22.5 at%) at the expense of Ni and Ti, respectively. By increasing the plate thickness of the casted samples from 500 μm to 1.25 mm, the primary precipitating phases are identified which is for the best glass-formers (e.g. Ti 58 Zr 7.5 Ni 18.5 Cu 12 S 4 ) an icosahedral phase. In calorimetric experiments, several exothermic crystallization events are observed upon heating glassy samples. The first exothermic event, obscuring the glass transition, is attributed to the formation of the icosahedral phase. As the icosahedral phase forms upon heating and cooling for the best glass-formers, the origin of the increased glass-forming ability might be attributed to a pronounced icosahedral short-range order in the liquid state, impeding the formation of the stable crystalline phases.

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Relaxation dynamics of Fe55Cr10Mo14C15B6 metallic glass explored by mechanical spectroscopy and calorimetry measurements

Liu

Madinehei

Pineda

et al. 2016

J Therm Anal Calorim

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6In this work, the mechanical relaxation dynamics of Fe55Cr10Mo14C15B6 metallic glass is explored by 7 mechanical spectroscopy. The temperature dependent loss modulus E''(T) shows the features of β 8 relaxation well below glass transition temperature Tg. This β relaxation can be well described in the 9 framework of anelastic theory by a thermal activated process with activation energy of 165 kJ mol -1 . 10Structural relaxation, also known as physical aging, has a large effect on the glass properties. The 11 activation energy spectrum of structural relaxation is characterized by differential scanning calorimetry 12 measuring the heat flow difference between as quenched and relaxed states. The obtained energy 13 spectrum is well described by a log-normal distribution with maximum probability activation energy of 14 176 kJ mol -1 . The obtained activation energy of structural relaxation is similar to that of β relaxation 15 observed from mechanical spectroscopy. Both values are also close to the Johari-Goldstein β relaxation 16 estimated by the empirical rule Eβ=26RTg. 17

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Fragility of iron-based glasses

Cited by 28 publications

References 21 publications

Nano-crystallisation and magnetic softening in Fe–B binary alloys induced by ultra-rapid heating

Nano-crystallisation and magnetic softening in Fe–B binary alloys induced by ultra-rapid heating

Bulk metallic glass formation in the (Ti,Zr)–(Ni,Cu)–S system

Relaxation dynamics of Fe55Cr10Mo14C15B6 metallic glass explored by mechanical spectroscopy and calorimetry measurements

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