Relaxation Behavior of Ca-Based Bulk Metallic Glasses

Senkov, O.N.; Miracle, D.B.

doi:10.1007/s11661-009-9981-3

Cited by 16 publications

(8 citation statements)

References 40 publications

(102 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The linear relationship between log 10 h and T g can also be found in Ref. [37][38][39]. Interestingly, the theoretical results clearly indicate that T g = 338K at h ≈ 10K/min.…”

Section: B Molecular Dynamics Of Supercooled and Glassy Gambogic Acidsupporting

confidence: 70%

Molecular relaxations in supercooled liquid and glassy states of amorphous gambogic acid: Dielectric spectroscopy, calorimetry, and theoretical approach

Phan

Thủy

et al. 2020

AIP Advances

View full text Add to dashboard Cite

The relaxation dynamics and thermodynamic properties of supercooled and glassy gambogic acid are investigated using both theory and experiment. We measure the temperature dependence of the relaxation times in three polymorphs (α−, β−, and γ− form). To gain insight into the relaxation processes, we propose a theoretical approach to quantitatively understand nature of these three relaxations. The α−relaxation captures cooperative motions of molecules while the β−process is mainly governed by local dynamics of a single molecule within the cage formed by its nearest neighbors. Based on quantitative agreement between theory and experimental data, our calculations clearly indicate that the β−process is a precursor of the structural relaxation and intramolecular motions are responsible for the γ−relaxation. Moreover, the approach is exploited to study effects of the heating process on alpha relaxation. We find that the heating rate varies logarithmically with Tg and 1000/Tg. These variations are qualitatively consistent with many prior studies. * Electronic address: anh.phanduc@phenikaa-uni.edu.vn † Electronic address: thuy.tran@inpc.vast.vn a long-range-disordered structure, which is temperature dependent. Its physical behaviors are liquid-like at high temperatures. However, at low temperatures, structural relaxation process is significantly slowed down. Physical mechanisms underlying the glassy dynamics remain mysterious.

show abstract

“…The linear relationship between log 10 h and T g can also be found in Ref. [37][38][39]. Interestingly, the theoretical results clearly indicate that T g = 338K at h ≈ 10K/min.…”

Section: B Molecular Dynamics Of Supercooled and Glassy Gambogic Acidsupporting

confidence: 70%

Molecular relaxations in supercooled liquid and glassy states of amorphous gambogic acid: Dielectric spectroscopy, calorimetry, and theoretical approach

Phan

Thủy

et al. 2020

AIP Advances

View full text Add to dashboard Cite

show abstract

“…In general, The temperature dependence of the viscosity is reflected in a fragility index (m = dlog g/d(T g /T)| T = Tg ). [29] Some researchers found that Poisson's ratio (and ductility) increases, [29][30][31] whereas the GFA decreases [32,33] with the increase of m. Ca-based BMGs generally show a low m value [30,34] as well as a good GFA. This fact also indicates that the Ca-based BMGs could exhibit the brittleness.…”

Section: Resultsmentioning

confidence: 99%

The Duality of Fracture Behavior in a Ca-based Bulk-Metallic Glass

Wang

Liaw

Senkov

et al. 2010

Metall Mater Trans A

Self Cite

View full text Add to dashboard Cite

Ca 65 Mg 15 Zn 20 bulk-metallic glass (BMG) exhibited a typical brittle fracture behavior during compressive loading at room temperature. Samples exploded into many small pieces after elastic deformation and no macroscopic plasticity was observed. The fracture surface demonstrated multiple fracture patterns, including typical metallic-glass vein patterns and glass mirror, mist, and hackle patterns. These observations show that Ca-based BMGs are subjected to multiple brittle fracture modes under compressive loading. Periodic nanoscale corrugations were found in the hackle region, which may indicate local plasticity for the brittle fracture.

show abstract

“…Therefore, it is feasible to take the interatomic potential as the basis to clarify the underlying physics of glass formation and predict the favored glass formation compositions for a given system. Previous research has indicated that Ca-Mg-based [14][15][16] glasses have properties, such as very low Young's and shear moduli, 17 low density, 18 and strong relaxation dynamics of the super-cooled liquid, 19 that distinguish them from transition-metal-based bulk metallic glasses. It has been reported that ternary Ca-Mg-Cu systems have a good GFA with the maximum diameters of up to 9 mm and 10 mm obtained in Ca 50 Mg 25 Cu 25 and Ca 50 Mg 22.5 Cu 27.5 , respectively.…”

Section: Introductionmentioning

confidence: 99%

Computational assisted design of the favored composition for metallic glass formation in a Ca–Mg–Cu system

Zhao

et al. 2017

RSC Adv.

View full text Add to dashboard Cite

To well predict the favored composition for metallic glass formation in a Ca-Mg-Cu system, a realistic interatomic potential was first constructed for the system and then applied to Monte Carlo simulations. The simulation not only predicts a hexagonal composition region for metallic glass formation, but also provides a favored sub-region within which the amorphization driving force is larger than that outside. The simulations show that the physical origin of glass formation is the solid solution collapsing when the solute atom exceeds the critical solid solubility. Further structural analysis indicates that the 1551 bond pairs (icosahedral-like) dominate in the favored sub-region. The large atomic size difference between Ca, Mg, and Cu extends the short-range landscape, and a microscopic image of the medium-range packing can be described as an extended network of pentagonal bipyramids entangled with four-fold and six-fold disclinations, together fulfilling the space of the metallic glasses. The predictions are well supported by the experimental observations reported to date and can provide guidance for the design of ternary glasses.

show abstract

Relaxation Behavior of Ca-Based Bulk Metallic Glasses

Cited by 16 publications

References 40 publications

Molecular relaxations in supercooled liquid and glassy states of amorphous gambogic acid: Dielectric spectroscopy, calorimetry, and theoretical approach

Molecular relaxations in supercooled liquid and glassy states of amorphous gambogic acid: Dielectric spectroscopy, calorimetry, and theoretical approach

The Duality of Fracture Behavior in a Ca-based Bulk-Metallic Glass

Computational assisted design of the favored composition for metallic glass formation in a Ca–Mg–Cu system

Contact Info

Product

Resources

About