scholarly journals Temperature dependence of mechanical properties and pressure sensitivity in metallic glasses below glass transition

2008 ◽  
Vol 88 (12) ◽  
pp. 1773-1790 ◽  
Author(s):  
V. Keryvin ◽  
K. Eswar Prasad ◽  
Y. Gueguen ◽  
J.-C. Sanglebœuf ◽  
U. Ramamurty
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Temperature Dependence ◽  
Metallic Glasses ◽  
Pressure Sensitivity

Reverse Plasticity in Nanoindentation

2007 ◽  
Vol 1049 ◽  
Author(s):  
Yongjiang Huang ◽  
Nursiani Indah Tjahyono ◽  
Jun Shen ◽  
Yu Lung Chiu
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glass Transition ◽  
Single Crystal ◽  
Metallic Glasses ◽  
Deformation Mechanisms ◽  
Glass Transition Temperatures ◽  
Loading Rates ◽  
Nanoindentation Experiment ◽  
Properties Of Materials

AbstractThis paper summarises our recent cyclic nanoindentation experiment studies on a range of materials including single crystal and nanocrystalline copper, single crystal aluminium and bulk metallic glasses with different glass transition temperatures. The unloading and reloading processes of the nanoindentation curves have been analysed. The reverse plasticity will be discussed in the context of plastic deformation mechanisms involved. The effect of loading rates on the mechanical properties of materials upon cyclic loading will also be discussed.

Thermal Stability of Bulk Metallic Glasses. Influence on Mechanical Properties

1998 ◽  
Vol 554 ◽  
Author(s):  
J. M. Pelletier ◽  
Y. Jacquemard ◽  
J. Perez ◽  
R. Perrier de la Bathie
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Glass Transition ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Atomic Mobility ◽  
Heating Rates ◽  
Characteristic Temperatures ◽  
Shear Elastic Modulus ◽  
Thermal Stability Of

AbstractTwo Zr-base bulk metallic glasses were investigated in the present work. DSC experiments were performed at different heating rates (dT/dt). Evolution of the characteristic temperatures, glass transition and onset of crystallisation, were determined as a function of dT/dt. Evolution of shear elastic modulus and internal friction are measured as a function of temperature and resulting microstructural evolution; these evolutions are related to variation of the atomic mobility.

scholarly journals Pressure Sensitivity of Plasticity in Metallic Glasses below Glass Transition: A Literature Review

2012 ◽  
Vol 706-709 ◽  
pp. 1318-1323 ◽  
Author(s):  
Vincent Keryvin ◽  
Jean Sebastien Brest ◽  
Patrice Longere ◽  
Adrien Anguet
Keyword(s):  
Glass Transition ◽  
Literature Review ◽  
Pressure Dependence ◽  
Metallic Glasses ◽  
Pressure Sensitivity

This paper deals with the pressure dependence of plasticity in metallic glasses below glass transition. Recent results indicate that some metallic glasses have such a dependence and that it increases with temperature (Keryvin et al., Phil. Mag., 88, 1773, 2008). We investigate the possibility that such a situation could be a common feature for all metallic glasses by performing a literature review. Results indicate that it is not strightforward to draw decisive conclusions.

Mechanical properties, glass transition temperature, and bond enthalpy trends of high metalloid Fe-based bulk metallic glasses

2008 ◽  
Vol 92 (16) ◽  
pp. 161910 ◽  
Author(s):  
X. J. Gu ◽  
S. Joseph Poon ◽  
Gary J. Shiflet ◽  
Michael Widom
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses

scholarly journals Elastic Properties and Glass Forming Ability of the Zr50Cu40Ag10 Metallic Alloy

2020 ◽  
Vol 310 ◽  
pp. 145-149 ◽  
Author(s):  
Ramil M. Khusnutdinoff ◽  
Anatolii V. Mokshin
Keyword(s):  
Glass Transition ◽  
Shear Modulus ◽  
Temperature Dependence ◽  
Elastic Properties ◽  
Metallic Glasses ◽  
Liquid Glass ◽  
Glass Forming Ability ◽  
Metallic Alloy ◽  
Poisson's Ratio ◽  
Glass Forming

The elastic properties of the Zr50Cu40Ag10 metallic alloy, such as the bulk modulus B, the shear modulus G, the Young’s modulus E and the Poisson’s ratio σ, are investigated by molecular dynamics simulation in the temperature range T=250–2000 K and at an external pressure of p=1.0 bar. It is shown that the liquid–glass transition is accompanied by a considerable increase in the shear modulus G and the Young’s modulus E (by more than 50%). The temperature dependence of the Poisson’s ratio exhibits a sharp fall from typical values for metals of approximately 0.32–0.33 to low values (close to zero), which are characteristic for brittle bulk metallic glasses. Non-monotonic temperature dependence of the longitudinal and transverse sound velocity near the liquid-glass transition is also observed. The glass forming ability of the alloy is evaluated in terms of the fragility index m. Its value is m≈64 for the Zr50Cu40Ag10 metallic glass, which is in a good agreement with the experimental data for the Zr-based metallic glasses.

The correlation between the pressure sensitivity and the fragility/glass transition temperature in bulk metallic glasses

2011 ◽  
Vol 357 (15) ◽  
pp. 3033-3035 ◽  
Author(s):  
L.F. Liu ◽  
Z.P. Cai ◽  
H.Q. Li ◽  
S.B. Guo ◽  
G.Y. Zhang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Pressure Sensitivity

Dependence of the Ultimate Properties of a SBR Rubber on Strain Rate and Temperature

1959 ◽  
Vol 32 (4) ◽  
pp. 992-1004 ◽  
Author(s):  
Thor L. Smith
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Temperature Dependence ◽  
Amorphous Polymers ◽  
Shift Factor ◽  
Ultimate Properties ◽  
Tensile Data ◽  
Small Deformations

Abstract The tensile strength and ultimate elongation of polymeric materials depend on both the temperature and experimental time scale. The mechanical properties of amorphous polymers at temperatures above their glass transition temperature Tg are more amenable to treatment in terms of molecular theories than are their mechanical properties at temperatures below Tg or the mechanical properties of crystalline polymers. For amorphous polymers at temperatures above Tg the viscoelastic properties in small deformations have been studied rather extensively, and several molecular theories—essentially identical—have been published. In contrast, few systematic studies have been made of the effect of time and temperature on the ultimate properties. Consequently, only a limited amount of data is available which can serve as a basis for developing and verifying molecular theories dealing with ultimate properties. A recent theory by F. Bueche treats the time and temperature dependence of tensile strength. According to his theory, the tensile strength for a given material is a universal function of a reduced time or a reduced strain rate, except at short times or high strain rates where the material approaches glasslike behavior. Also, to superpose data measured at different temperatures, a shift factor is needed which is determined by the temperature dependence of the frictional factor for polymeric segment mobility and thus is the same factor as used to superpose viscoelastic data measured in small deformations. Thus, according to Bueche's theory, the temperature dependence of the tensile strength is given by the equation of Williams, Landel, and Ferry which is applicable in the temperature range Tg<T<(Tg+100). Bueche reported some tensile data for polybutyl methacrylate which has a glass transition temperature of 8° C. These tensile data were measured under various constant loads at temperatures between 30 and 95° C, and reasonable agreement between theory and experiment was found. Although Bueche did not consider the ultimate elongation, it seems reasonable that such data can be superposed by using the same shift factor as required to superpose the tensile strength data. Other workers have not considered explicitly the effect of viscous forces on the ultimate properties but have considered the effect of such variables as molecular weight, degree of crosslinking, and plasticizers.

scholarly journals Studies on the Modification of Commercial Bisphenol-A-Based Epoxy Resin Using Different Multifunctional Epoxy Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Tensile Fracture ◽  
Chemical Structures ◽  
Amino Phenol ◽  
Epoxy Systems

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.

scholarly journals Synthesis, Properties, and Biodegradability of Thermoplastic Elastomers Made from 2-Methyl-1,3-propanediol, Glutaric Acid and Lactide

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Lamya Zahir ◽  
Takumitsu Kida ◽  
Ryo Tanaka ◽  
Yuushou Nakayama ◽  
Takeshi Shiono ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glutaric Acid ◽  
Triblock Copolymers ◽  
Tensile Tests ◽  
Thermoplastic Elastomers ◽  
Proteinase K ◽  
Synthesis Properties

An innovative type of biodegradable thermoplastic elastomers with improved mechanical properties from very common and potentially renewable sources, poly(L-lactide)-b-poly(2-methyl-1,3-propylene glutarate)-b-poly(L-lactide) (PLA-b-PMPG-b-PLA)s, has been developed for the first time. PLA-b-PMPG-b-PLAs were synthesized by polycondensation of 2-methyl-1,3-propanediol and glutaric acid and successive ring-opening polymerization of L-lactide, where PMPG is an amorphous central block with low glass transition temperature and PLA is hard semicrystalline terminal blocks. The copolymers showed glass transition temperature at lower than −40 °C and melting temperature at 130–152 °C. The tensile tests of these copolymers were also performed to evaluate their mechanical properties. The degradation of the copolymers and PMPG by enzymes proteinase K and lipase PS were investigated. Microbial biodegradation in seawater was also performed at 27 °C. The triblock copolymers and PMPG homopolymer were found to show 9–15% biodegradation within 28 days, representing their relatively high biodegradability in seawater. The macromolecular structure of the triblock copolymers of PLA and PMPG can be controlled to tune their mechanical and biodegradation properties, demonstrating their potential use in various applications.

Effects of Al replacement on glass forming ability and mechanical properties of Zr-based bulk metallic glasses

2021 ◽  
Vol 568 ◽  
pp. 120962
Author(s):  
Y. Tan ◽  
Y.W. Wang ◽  
X.W. Cheng ◽  
Q. Fu ◽  
Z.H. Xin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Glass Forming Ability ◽  
Glass Forming
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