Electron Irradiation Effect on the Microstructure and Phase Stability of Fe-Based Fe71.0Zr9.0B20.0 Metallic Glass with a Wide Supercooled Liquid Region

2002 ◽  
Vol 754 ◽  
Author(s):  
T. Nagase ◽  
Y. Umakoshi ◽  
N. Sumida
Keyword(s):  
Metallic Glass ◽  
Amorphous Phase ◽  
Electron Irradiation ◽  
Phase Stability ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Microstructural Change ◽  
Irradiation Effect ◽  
Liquid Region ◽  
Melt Spun

ABSTRACTThe effect of electron irradiation on the microstructural change and phase stability of melt-spun Fe71.0Zr9.0B20.0 metallic glass having a wide supercooled liquid region of 71 K was examined. Crystallization from the amorphous phase was accelerated by electron irradiation, and this irradiation was effective in producing a nanocomposite microstructure.

Effects of Additional Elements on Microstructures of Zr-Based Metallic Glass Ribbons

2007 ◽  
Vol 539-543 ◽  
pp. 2000-2005
Author(s):  
Tokujiro Yamamoto ◽  
Noriharu Yodoshi ◽  
Hisamichi Kimura ◽  
Akihisa Inoue
Keyword(s):  
Mechanical Properties ◽  
Metallic Glass ◽  
Phase Stability ◽  
Glass Phase ◽  
Supercooled Liquid ◽  
Enthalpy Of Mixing ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Al Addition ◽  
Fe Addition

Effects of Fe, Co and Al addition to Zr55Al10Ni5Cu30 and Zr70Cu30 metallic glass ribbons were studied. 20 at.% of Fe addition prevented Zr55Al10Ni5Cu30 molten alloys from being supercooled and resulted in nanocrystallization, while Zr55Al10Ni5Cu30 alloys containing 20 at.% Co could be quenched into a supercooled liquid region. Fe addition also degraded Zr70Cu30 metallic glass, while Al addition improved both glass phase stability and mechanical properties. Degradation of Zr-based metallic glass by Fe addition originates in the large negative enthalpy of mixing Fe with Cu.

Plasticity in Bulk Metallic Glass Composites Containing Dual Amorphous Phases

2007 ◽  
Vol 539-543 ◽  
pp. 2026-2030 ◽  
Author(s):  
J.K. Lee ◽  
H.J. Kim ◽  
Taek Soo Kim ◽  
Jung Chan Bae
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Amorphous Phase ◽  
Glass Matrix ◽  
Supercooled Liquid ◽  
Amorphous Structure ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Glass Composites ◽  
Amorphous Phases

Bulk metallic glass (BMG) composites with dual amorphous phases were fabricated by spark plasma sintering of a mixture of Cu-based and Zr-based amorphous powders in their overlapped supercooled liquid region. The Zr-based amorphous phases are well distributed homogeneously in the Cu-based metallic glass matrix after consolidation. The BMG composite still remains as an amorphous structure after consolidation. The BMG composite with dual amorphous phases shows macroscopic plasticity after yielding, and the plastic strain increased to around 3.4% in the BMG composite containing 30 vol% Zr-based amorphous phase. The successful consolidation of BMG composite with enhanced plasticity was achieved by introducing a second amorphous phase in the metallic glass matrix.

scholarly journals Effects of Annealing on Enthalpy Recovery and Nanomechanical Behaviors of a La-Based Bulk Metallic Glass

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 579
Author(s):  
Ting Shi ◽  
Lanping Huang ◽  
Song Li
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Structural Relaxation ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Nanoindentation Measurement

Structural relaxation and nanomechanical behaviors of La65Al14Ni5Co5Cu9.2Ag1.8 bulk metallic glass (BMG) with a low glass transition temperature during annealing have been investigated by calorimetry and nanoindentation measurement. The enthalpy release of this metallic glass is deduced by annealing near glass transition. When annealed below glass transition temperature for 5 min, the recovered enthalpy increases with annealing temperature and reaches the maximum value at 403 K. After annealed in supercooled liquid region, the recovered enthalpy obviously decreases. For a given annealing at 393 K, the relaxation behaviors of La-based BMG can be well described by the Kohlrausch-Williams-Watts (KWW) function. The hardness, Young’s modulus, and serrated flow are sensitive to structural relaxation of this metallic glass, which can be well explained by the theory of solid-like region and liquid-like region. The decrease of ductility and the enhancement of homogeneity can be ascribed to the transformation from liquid-like region into solid-like region and the reduction of the shear transition zone (STZ).

Flow Stress and Elongation of Superplastic Deformation in La55Al25Ni20 Metallic Glass

1999 ◽  
Vol 601 ◽  
Author(s):  
Y. Kawamura ◽  
A. Inoue
Keyword(s):  
Flow Stress ◽  
Metallic Glass ◽  
Strain Rate ◽  
Superplastic Deformation ◽  
Constant Strain Rate ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Elongation To Failure ◽  
Crosshead Velocity

AbstractWe have investigated the flow stress and elongation of superplastic deformation in a La55Al25Ni20 (at%) metallic glass that has a wide supercooled liquid region of 72 K before crystallization. The superplasticity that appeared in the supercooled liquid region was generated by the Newtonian viscous flow that exhibits the m value of unity. The elongation to failure was restricted by the transition of the Newtonian flow to non-Newtonian one and the crystallization during deformation. We succeeded in establishing the constitutive formulation of the flow stress in the supercooled liquid region. Its formulation was expressed very well by a stretched exponential function σflow=Dε exp(H*/RT) [1-exp(E/{ε exp(H**/RT)}0.82)]. Formulations describing the elongation to failure in constant-strain-rate and constant-crosshead velocity tests were, moreover, established. It was found from the simulation that the maximum elongation in the constant-strain-rate test reached more than 106% which was two orders of magnitude larger than that in the constant-crosshead-velocity test.

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