Plastic Deformation of Glassy Polymers:  Correlation between Shear Activation Volume and Entanglement Density

2003 ◽  
Vol 36 (19) ◽  
pp. 7398-7404 ◽  
Author(s):  
Janet Ho ◽  
Leon Govaert ◽  
Marcel Utz
Keyword(s):  
Plastic Deformation ◽  
Activation Volume ◽  
Glassy Polymers ◽  
Entanglement Density

Plastic Deformation of Glassy Polymers: Correlation Between Shear Activation Volume and Entanglement Density

2002 ◽  
Vol 734 ◽  
Author(s):  
Janet Ho ◽  
Leon Govaert ◽  
Marcel Utz
Keyword(s):  
Plastic Deformation ◽  
Plane Strain ◽  
Activation Volume ◽  
Shear Zones ◽  
Glassy Polymers ◽  
Strain Rates ◽  
Plastic Shear ◽  
Elementary Processes ◽  
Entanglement Density ◽  
Phenylene Oxide

ABSTRACTThe shear activation volumes of miscible polystyrene-poly(2,6-dimethyl-1,4-phenylene oxide) (PS-PPO) blends at different PS-PPO ratios were determined experimentally by both plane strain and uniaxial compression at constant strain rates. We find that the same correlation between the shear activation volume and the entanglement density ρe holds for the blend as well as for various pure glassy polymers: . Since the shear activation volume is closely related to the size of the plastic shear zones, this correlation suggests that the cooperativity of the elementary processes of plastic deformation in glassy polymers scales with the entanglement density.

Hard and Soft: Principles of Polyner-Impregnated Concrete Using Elastomers

2013 ◽  
Vol 687 ◽  
pp. 118-123 ◽  
Author(s):  
Oliver Weichold ◽  
Udo Antons
Keyword(s):  
Plastic Deformation ◽  
Fracture Mechanics ◽  
Brittle Failure ◽  
Elastic Moduli ◽  
Domain Size ◽  
Glassy Polymers ◽  
Crack Deflection ◽  
Micro Cracks ◽  
Concrete Interface ◽  
Crystalline Matrix

The effect of incorporating elastomeric domains in concrete is described from the point of fracture mechanics. Concrete is subject to brittle failure, since cracks propagate at an enormous speed in the crystalline matrix. However, micro cracks are attracted to volume elements with lower elastic moduli such as elastomeric domains. Cracks that encounter the concrete-elastomer interface are stopped since energy is dissipated by plastic deformation of and/or crack deflection by the elastomer. The domain size and the distribution of the elastomer as well as, and properties of the elastomer-concrete interface are crucial parameters. Such a combination differs substantially from previously prepared polymer-impregnated concretes, in which only glassy polymers were used.

Activation volume and strain rate sensitivity in plastic deformation of nanocrystalline Ti

2013 ◽  
Vol 228 ◽  
pp. S254-S256 ◽  
Author(s):  
F. Wang ◽  
B. Li ◽  
T.T. Gao ◽  
P. Huang ◽  
K.W. Xu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Activation Volume ◽  
Rate Sensitivity

Plastic deformation in glassy polymers by atomistic and mesoscopic simulations

1995 ◽  
Vol 39 (2) ◽  
pp. 377-399 ◽  
Author(s):  
A. S. Argon ◽  
V. V. Bulatov ◽  
P. H. Mott ◽  
U. W. Suter
Keyword(s):  
Plastic Deformation ◽  
Glassy Polymers ◽  
Mesoscopic Simulations

Indentation Stress Relaxation Behavior in As-Deposited and Rolling Nanocrystalline NiFe

2013 ◽  
Vol 745-746 ◽  
pp. 352-356
Author(s):  
Z.H. Cao ◽  
Xiang Kang Meng
Keyword(s):  
Plastic Deformation ◽  
Stress Relaxation ◽  
Dislocation Density ◽  
Indentation Depth ◽  
Activation Volume ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Hardening Behavior ◽  
Rolling Deformation ◽  
Dislocation Multiplication

The stress relaxation behavior of as-deposited and rolling nanocrystalline NiFe alloy was studied by nanoindentation tests. The results indicated that both the hardness and activation volume of rolling NiFe are larger than that of as-deposited samples. Furthermore, the hardness decreases with increasing indentation depth. The reduction of indentation stress during holding becomes much faster with decreasing the indentation depth. Dislocation density is remarkably enhanced by rolling deformation, leading to the hardening behavior. Dislocation multiplication and accumulation mediated process is believed to the dominant plastic deformation mechanism.

Activation volume analysis of plastic deformation in fcc materials using nanoindentation

2002 ◽  
Vol 750 ◽  
Author(s):  
A. A. Elmustafa ◽  
M. F. Tambwe ◽  
D. S. Stone
Keyword(s):  
Thin Films ◽  
Plastic Deformation ◽  
Activation Volume ◽  
Hardness Measurement ◽  
Silicon Substrates ◽  
Polycrystalline Aluminum ◽  
Volume Analysis ◽  
Fcc Metals ◽  
Nickel Thin Films ◽  
Fcc Materials

ABSTRACTActivation volumes for plastic deformation of fcc metals are measured using nanoindentation. Materials include bulk, polycrystalline aluminum and α-brass, and sputtered copper and nickel thin films on silicon substrates. From a hardness measurement, V* is defined as 9kBT/∂H/∂ln , where H is the hardness and is a representative strain rate beneath the indenter. Data obtained using nanoindentation are consistent with those obtained using more conventional experiments based on uniaxial loading.

Change in Activation Volume for Plastic Deformation of Zr-based Bulk Metallic Glass following Annealing

2007 ◽  
Vol 1048 ◽  
Author(s):  
Jonathan B. Puthoff ◽  
Donald S. Stone ◽  
Hongbo Cao ◽  
Paul M. Voyles
Keyword(s):  
Plastic Deformation ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Activation Volume ◽  
Cast Alloy ◽  
Transformation Zone ◽  
Alloy Hardness ◽  
Shear Transformation ◽  
Shear Transformation Zone ◽  
The Individual

AbstractWe performed nanoindentation creep experiments on the bulk metallic glass Zr54Cu38Al8 in an effort to measure the scale of the individual deformation events responsible for plastic deformation. From a nanoindentation creep experiment, we can determine V*, the activation volume, which we interpret as the volume of a shear transformation zone (STZ) multiplied by the shear strain undergone by the STZ during thermal activation. For the as-cast alloy hardness, H, is 5.33 ± 0.06 GPa, and V* is 87 ± 5 Å3. The alloy was then annealed near Tg for 24 hr and retested. No crystallization occurred during annealing as verified by XRD and TEM. Following annealing H increased to 7.36 ± 0.08 GPa and V* increased to 160 ± 10 Å3. We interpret the change in V* as arising from an increase in the number of atoms involved in the STZ.

Effect of intermolecular interactions on the plastic deformation of glassy polymers

Polymer ◽  
1996 ◽  
Vol 37 (7) ◽  
pp. 1177-1181 ◽  
Author(s):  
Masaru Ishikawa ◽  
Yoko Sato ◽  
Hiroaki Higuchi
Keyword(s):  
Plastic Deformation ◽  
Intermolecular Interactions ◽  
Glassy Polymers
Sign in / Sign up

Export Citation Format

Share Document