Finite-element analysis for high-temperature deformation of bulk metallic glasses in a supercooled liquid region based on the free volume constitutive model

2010 ◽  
Vol 58 (12) ◽  
pp. 4267-4280 ◽  
Author(s):  
H-J. Jun ◽  
K.S. Lee ◽  
S.C. Yoon ◽  
H.S. Kim ◽  
Y.W. Chang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Metallic Glasses ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Liquid Region ◽  
Element Analysis

High Temperature Deformation in the Amorphous or Partially Crystallized Zr41.2Ti13.8Cu12.5Ni10Be22.5 Bulk Metallic Glass

2002 ◽  
Vol 754 ◽  
Author(s):  
Q. Wang ◽  
J.J. Blandin ◽  
M. Suery ◽  
J.M. Pelletier
Keyword(s):  
High Temperature ◽  
Metallic Glass ◽  
Strain Rate ◽  
Bulk Metallic Glass ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Liquid Region ◽  
Newtonian Behavior

ABSTRACTThe high temperature deformation of the Zr41.2Ti12.5Cu13.8Ni10Be22.5 bulk metallic glass (BMG) is studied in the supercooled liquid region. Both fully amorphous and partially crystallized states are investigated. In the studied experimental domain, the amorphous alloy exhibits a Newtonian behavior at high temperature and/or low strain rate whereas a transition to non-Newtonian behavior is observed when the temperature is decreased and/or the strain rate is increased. In the Newtonian domain, the dependency of the viscosity upon temperature can be described by an Arrhénius law. As far as the as-received alloy is maintained at high temperature for which phase separation and primary crystallisation is expected, the flow stress continuously increases, which is at least partly attributed to a change in the residual amorphous phase.

High Temperature Deformation Characteristics of Zr76.11Ti4.20Cu4.51Ni3.16Be1.49Nb10.53 Bulk Metallic Glass Composite

2007 ◽  
Vol 539-543 ◽  
pp. 2111-2116 ◽  
Author(s):  
H.J. Jun ◽  
Kwang Seok Lee ◽  
Yeon Chul Yoo ◽  
Young Won Chang
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Glassy Matrix ◽  
Liquid Region ◽  
Compression Tests ◽  
Bcc Structure

The thermal properties of a Zr76.11Ti4.20Cu4.51Ni3.16Be1.49Nb10.53 bulk metallic glass (BMG) have been investigated by using a differential scanning calorimeter (DSC). The composition of dendrite phase was then subsequently analyzed by using an EPMA, XRD, and TEM. The glass transition and crystallization onset temperatures were determined as 339.7 °C and 375.8 °C for this BMG, respectively. The Zr-Ti-Nb dendrite phase was found to have a BCC structure. Mechanical properties have also been examined by conducting a series of uniaxial compression tests at various temperatures within supercooled liquid region under the strain rates between 10-4 /s and 3×10-2 /s. The hardness of matrix and dendrite was then measured separately. The glassy matrix appears to play major role on the elongation, while dendrite phase on the strength of this BMG composite at high temperatures within supercooled liquid region.

High Temperature Forming Maps of Various Bulk Metallic Glasses

2010 ◽  
Vol 433 ◽  
pp. 345-351 ◽  
Author(s):  
Jennifer Ragani ◽  
Q. Wang ◽  
Sébastien Gravier ◽  
Jean Jacques Blandin
Keyword(s):  
High Temperature ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Large Strains ◽  
Liquid Region ◽  
Compression Tests ◽  
Partial Crystallization ◽  
Temperature Time

Due to their brittleness, bulk metallic glasses (BMG) are generally difficult to form at room temperature. Casting of BMG is one way to get components but an alternative route is to use the capacity to reach particularly large strains when the glasses are deformed in their supercooled liquid region (SLR). The experimental window (temperature, time) in which high temperature forming can be carried out is directly related to the glass resistance to crystallization. Such forming windows have been identified for various bulk metallic glasses (mainly zirconium and magnesium based BMG) thanks to compression tests in the supercooled liquid region. The effects of partial crystallization on the high temperature rheologies are also discussed. Finally, forming experiments were carried out in the selected windows.

scholarly journals Investigation of the Structural Heterogeneity and Corrosion Performance of the Annealed Fe-Based Metallic Glasses

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 929
Author(s):  
Dandan Liang ◽  
Jo-Chi Tseng ◽  
Xiaodi Liu ◽  
Yuanfei Cai ◽  
Gang Xu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Passive Film ◽  
Metallic Glasses ◽  
Function Analysis ◽  
Supercooled Liquid ◽  
Structural Heterogeneity ◽  
Coordination Shell ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Corrosion Performance

This study investigated the structural heterogeneity, mechanical property, electrochemical behavior, and passive film characteristics of Fe–Cr–Mo–W–C–B–Y metallic glasses (MGs), which were modified through annealing at different temperatures. Results showed that annealing MGs below the glass transition temperature enhanced corrosion resistance in HCl solution owing to a highly protective passive film formed, originating from the decreased free volume and the shrinkage of the first coordination shell, which was found by pair distribution function analysis. In contrast, the enlarged first coordination shell and nanoscale crystal-like clusters were identified for MGs annealed in the supercooled liquid region, which led to a destabilized passive film and thereby deteriorated corrosion resistance. This finding reveals the crucial role of structural heterogeneity in tuning the corrosion performance of MGs.

Creep Modeling of Welded Joints Using the Theta Projection Concept and Finite Element Analysis

1999 ◽  
Vol 122 (1) ◽  
pp. 22-26 ◽  
Author(s):  
M. Law ◽  
W. Payten ◽  
K. Snowden
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Welded Joints ◽  
Creep Model ◽  
Projection Data ◽  
Predictive Capability ◽  
Element Analysis ◽  
High Temperature And Pressure ◽  
Temperature And Pressure

Modeling of welded joints under creep conditions with finite element analysis was undertaken using the theta projection method. The results were compared to modeling based on a simple Norton law. Theta projection data extends the accuracy and predictive capability of finite element modeling of critical structures operating at high temperature and pressure. In some cases analyzed, it was found that the results diverged from those gained using a Norton law creep model. [S0094-9930(00)00601-6]

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