Free-volume changes in the bulk metallic glass<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Zr</mml:mi></mml:mrow><mml:mrow><mml:mn>46.7</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ti</mml:mi></mml:mrow><mml:mrow><mml:mn>8.3</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Cu</mml:mi></mml:mrow><mml:mrow><mml:mn>7.5

Nagel, Christoph; Rätzke, Klaus; Schmidtke, E.; Wolff, Jonas; Geyer, U.; Faupel, Franz

doi:10.1103/physrevb.57.10224

Cited by 152 publications

(75 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Free volume change induced by plastic deformation has been investigated by using various techniques such as positron annihilation, 9,10) direct density measurement, 11,12) TEM and SEM observation, 2,3) fluctuation electron microscopy, 13) and so on. However, the experimental techniques have inherent limitations in spatial and temporal resolutions; and most tests have to be performed after sample failure.…”

Section: Introductionmentioning

confidence: 99%

Free Volume Evolution in Metallic Glasses Subjected to Mechanical Deformation

2007

Mater. Trans.

View full text Add to dashboard Cite

We define the Turnbull-Cohen free volume as the critical excess of the Voronoi volume of an atom less its core volume. Using molecular dynamics simulation we calculated the free volume change in two model binary metallic glasses undergoing tension and shear deformation. We show that the free volume change is an integral part of the deformation process; and the shear localization manifested as a shear band is directly related to the inhomogeneous distribution of the free volumes. Shear band formation may consist of two stages: the initial free volume production in the amorphous solids and the liquefaction of the regions with accumulated deformation strains. We show, for the first time, the formation of voids and the ''vein'' patterns on fracture surfaces at atomic scales; they are the combined result of the free volume change and loading and sample conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Free Volume Evolution in Metallic Glasses Subjected to Mechanical Deformation

2007

Mater. Trans.

View full text Add to dashboard Cite

show abstract

“…Enthalpy relaxation 6) experiments suggested similarly that the process is well described by a stretched exponential type relaxation function. Regarding still direct measurement to investigate the relaxation process, the positron annihilation experiments were carried out for a ZrBe based bulk glass 7) to investigate the kinetics of free volume reduction during relaxation. The positron life-time was well described by a stretched exponential function.…”

Section: Introductionmentioning

confidence: 99%

Precise Measurement of Density in the Isothermal Relaxation Processes of Pd42.5Cu30Ni7.5P20 and Zr50Cu40Al10 Glasses

2007

View full text Add to dashboard Cite

The isothermal relaxation processes of bulk Zr 50 Cu 40 Al 10 and Pd 42:5 Cu 30 Ni 7:5 P 20 glasses were examined by density reduction associated with relaxation. Density experiments were carried out by buoyancy method at room temperature. The isothermal relaxation curves were best fitted by a stretched exponential function with a Kohlrausch exponent less than unity. Based on free volume model, the reduced free volume x as f ¼ 0:0355 and flow defect concentration C as f ¼ 5:80 Â 10 À13 in as-quenched state was obtained for Pd 42:5 Cu 30 Ni 7:5 P 20 glass. However, the temperature at which the free volume started to deviate from equilibrium concentration on cooling of the melt was not in accordance with calorimetric glass transition temperature.

show abstract

“…However, for metallic glasses the dynamical relaxation can be measured only by mechanical analysis where the shear modulus and the mechanical loss are measured as a function of temperature and frequency. The structural relaxation can be observed by various SRA measurements of a variety of physical properties, such as viscosity, 611) positron annihilation lifetime, 12,13) enthalpy, 11,1416,19,20) and volume 11,1720) as well as mechanical properties. 21) Structural relaxation was reported by Fan 14) by means of enthalpy relaxation in a temperature range just below T g for Pd 43 Cu 27 Ni 10 P 20 BMG.…”

Section: Introductionmentioning

confidence: 99%

Volume and Enthalpy Relaxation in Pd42.5Cu30Ni7.5P20 Bulk Metallic Glass

et al. 2014

View full text Add to dashboard Cite

The kinetics of structural relaxation in Pd 42.5 Cu 30 Ni 7.5 P 20 bulk metallic glass (BMG) was investigated by means of volume relaxation and enthalpy relaxation in the temperature range below T g (µ 573 K). The measured relaxation time was significantly longer than the ¡-relaxation time reported by dynamical mechanical analysis (DMA), indicating that these two relaxation processes are fundamentally different from each other. The temperature dependence of electrical resistivity suggests that the origin of the ¢-relaxation process that occurs between room temperature and T g may be the compositional short range ordering. Anomalous volume expansion was observed in the initial stage of relaxation, which was attributed to annihilation of the p-type defects with very short relaxation time.

show abstract

Free-volume changes in the bulk metallic glassZr46.7Ti8.3Cu7.5

Cited by 152 publications

References 26 publications

Free Volume Evolution in Metallic Glasses Subjected to Mechanical Deformation

Free Volume Evolution in Metallic Glasses Subjected to Mechanical Deformation

Precise Measurement of Density in the Isothermal Relaxation Processes of Pd<SUB>42.5</SUB>Cu<SUB>30</SUB>Ni<SUB>7.5</SUB>P<SUB>20</SUB> and Zr<SUB>50</SUB>Cu<SUB>40</SUB>Al<SUB>10</SUB> Glasses

Volume and Enthalpy Relaxation in Pd<sub>42.5</sub>Cu<sub>30</sub>Ni<sub>7.5</sub>P<sub>20</sub> Bulk Metallic Glass

Contact Info

Product

Resources

About