Articles you may be interested inEffect of physical aging on Johari-Goldstein relaxation in La-based bulk metallic glass Evidence for viscous flow nature in Zr60Al15Ni25 metallic glass subjected to cold rolling Dynamic mechanical analysis in La-based bulk metallic glasses: Secondary (β) and main (α) relaxations J. Appl. Phys. 112, 083528 (2012); 10.1063/1.4759284 Heating and structural disordering effects of the nonlinear viscous flow in a Zr 55 Al 10 Ni 5 Cu 30 bulk metallic glass Appl.

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Articles you may be interested inTunable magnetic and magnetocaloric properties in heavy rare-earth based metallic glasses through the substitution of similar elements Magnetocaloric effect of Ho-, Dy-, and Er-based bulk metallic glasses in helium and hydrogen liquefaction temperature range Appl. Phys. Lett. 90, 211903 (2007); 10.1063/1.2741120Behavior of some heavy and light rare earth-cobalt magnets at high temperature Electronegativity of the constituent rare-earth metals as a factor stabilizing the supercooled liquid region in Albased metallic glasses (RE ¼ Gd, Dy, and Tm) high-entropy bulk metallic glasses (HE-BMGs) with good magnetocaloric properties are fabricated successfully. The HE-BMGs exhibit a second-order magnetic phase transition. The peak of magnetic entropy change (DS pk M ) and refrigerant capacity (RC) reaches 15.0 J kg À1 K À1 and 627 J kg À1 at 5 T, respectively, which is larger than most rare earth based BMGs. The heterogeneous nature of glasses also contributes to the large DS pk M and RC. In addition, the magnetic ordering temperature, DS pk M and RC can be widely tuned by alloying different rare earth elements. These results suggest that the HE-BMGs are promising magnetic refrigerant at low temperatures. V C 2015 AIP Publishing LLC.

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We report that even in quasi-static cyclic compressions in the apparent elastic regimes of the bulk metallic glasses, the precisely measured stress-strain curve presents a mechanical hysteresis loop, which is commonly perceived to occur only in high-frequency dynamic tests. A phenomenological viscoelastic model is established to explain the hysteresis loop and demonstrate the evolutions of the viscous zones in metallic glasses during the cyclic compression. The declining of the viscosity of the viscous zones to at least 1 × 1012 Pa s when stress applied indicates that stress-induced localized glass to supercooled liquid transition occurs. We show that the deformation units of metallic glasses are evolved from the intrinsic heterogeneous defects in metallic glasses under stress and the evolution is a manifestation of the stress-induced localized glass transition. Our study might provide a new insight into the atomic-scale mechanisms of plastic deformation of metallic glasses.

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a b s t r a c tWe develop a quantitative analysis of how the plastic deformation in a metallic glass is more uniform if its Poisson ratio n is higher. The plasticity of metallic glasses under ambient conditions is mediated by shear localized in thin bands, and can be characterized by experiments on the bending of thin plates. We extend the analysis by Conner et al. (Conner et al., J. Appl. Phys. 94 (2003), 904-911) of bands in bent plates to include the micromechanics of individual shear bands. Expressions are derived for the shearband spacing and the offset on each band. Both these quantities are predicted to decrease as n is increased. The predictions are tested against measurements on metallic glasses with a wide range of n.Good agreement is found, supporting the new model for the shear-band spacing, and pointing the way towards more diffuse deformation, and consequently improved plasticity and toughness, of metallic glasses as n increases toward the limiting value of 0.5. Crown

The unique thermoplastic forming ability of metallic glasses in their supercooled liquid state makes them the ideal embossing materials for miniature fabrication. However, the understanding and controlling of micro filling process that is crucial for miniature fabrication and their applications remain fundamental, yet presently unresolved issues. Here, the mold filling kinetics of a model Pd-based metallic glass in supercooled liquid state is studied using different Si micro molds with different channels. A universal kinetic equation, which can describe the filling kinetics of viscous metallic supercooled liquid in micro molds with irregular shapes, is obtained.