On Gradient Nanomechanics: Plastic Flow in Nanopolycrystals

2010 ◽  
Vol 667-669 ◽  
pp. 991-996 ◽  
Author(s):  
Xu Zhang ◽  
A.E. Romanov ◽  
Elias C. Aifantis
Keyword(s):  
Grain Size ◽  
Plastic Strain ◽  
Continuum Mechanics ◽  
Evolution Equations ◽  
Surface Interactions ◽  
Structural Defects ◽  
Field Equations ◽  
Size Dependent ◽  
Bulk Surface ◽  
Generalized Continuum

Gradient nanomechanics is a generalized continuum mechanics framework accounting for “bulk-surface” interactions in the form of gradient terms that enter in the evolution equations of the relevant constitutive variables and/or in the governing field equations. This approach is discussed in the paper by developing appropriate differential equations for the plastic strain and/or the structural defects that bring this about. The effectiveness of the approach is illustrated by considering size-dependent stress-strain curves for nanopolycrystals with varying grain size.

A Critical Review of Existing Hydrogen Diffusion Models Accounting for Different Physical Variables

2014 ◽  
Vol 225 ◽  
pp. 13-18 ◽  
Author(s):  
Jesús Toribio ◽  
Viktor Kharin
Keyword(s):  
Plastic Strain ◽  
Continuum Mechanics ◽  
Critical Review ◽  
Hydrogen Diffusion ◽  
Hydrostatic Stress ◽  
Stress And Strain ◽  
Material Microstructure ◽  
Continuum Modelling ◽  
Physical Variables ◽  
Cumulative Plastic Strain

The present paper offers a continuum modelling of trap-affected hydrogen diffusion in metals and alloys, accounting for different physical variables of both macroscopic nature (i.e., related to continuum mechanics, e.g., stress and strain) and microscopic characteristics (material microstructure, traps, etc.). To this end, the model of hydrogen diffusion assisted by the gradients of both hydrostatic stress and cumulative plastic strain,stress-and-strain assisted hydrogen diffusion, proposed and frequently used by the authors of the present paper (Toribio & Kharin) is analysed in addition to other well-known models such as those proposed by (i) McNabb & Foster, (ii) Oriani, (iii) Leblond & Dubois, (iv) Sofronis & McMeeking, (v) Krom and Bakker, showing their physical and mathematical differences and similarities to account for different physical variables.

Grain-size-dependent gas-sensing properties of TiO2 nanomaterials

2015 ◽  
Vol 211 ◽  
pp. 67-76 ◽  
Author(s):  
B. Lyson-Sypien ◽  
M. Radecka ◽  
M. Rekas ◽  
K. Swierczek ◽  
K. Michalow-Mauke ◽  
...  
Keyword(s):  
Grain Size ◽  
Gas Sensing ◽  
Sensing Properties ◽  
Size Dependent ◽  
Gas Sensing Properties ◽  
Tio2 Nanomaterials

Grain size dependent tensile behavior of Mg–3%Al alloy at elevated temperatures

2009 ◽  
Vol 515 (1-2) ◽  
pp. 14-18 ◽  
Author(s):  
Ashis Mallick ◽  
Srikanth Vedantam ◽  
Li Lu
Keyword(s):  
Grain Size ◽  
Elevated Temperatures ◽  
Tensile Behavior ◽  
Al Alloy ◽  
Size Dependent

Controlling Grain Size in Oxide Ceramics for Optimization of Strength and Wear Resistance

2012 ◽  
Vol 715-716 ◽  
pp. 703-710
Author(s):  
W.M. Rainforth ◽  
P. Zeng ◽  
L. Ma
Keyword(s):  
Grain Size ◽  
Sliding Wear ◽  
Second Phase ◽  
Alumina Ceramics ◽  
Size Dependent ◽  
Mild Wear ◽  
Accumulation Mechanism ◽  
Wear Transition ◽  
Magnitude Increase ◽  
Zirconia Toughened Alumina

t is well known that alumina ceramics undergo a time dependent wear transition during sliding wear. The transition, which is associated with 1-2 orders of magnitude increase in specific wear rate, involves a change from mild wear to intergranular fracture. The transition is strongly grain size dependent, with the time to the transition decreasing with grain size. However, there is a minimum grain size that can be achieved in fully dense alumina using commercially viable processing. Alternative strategies for reducing grain size and increasing toughness are through the addition of a fine second phase, with SiC and ZrO2being the most promising. The resultant composite not only has finer grain size, but also exhibits additional toughening mechanisms. This paper reports on the microstructural control in alumina, zirconia toughened alumina and alumina-silicon carbide composites. The grain size and residual stress distribution are related to the damage accumulation mechanism that occur during frictional contact, in particular the surface specific dislocation activity.

Grain size-dependent viscosity convection and the thermal evolution of the Earth

2001 ◽  
Vol 191 (3-4) ◽  
pp. 203-212 ◽  
Author(s):  
V.S. Solomatov
Keyword(s):  
Grain Size ◽  
Thermal Evolution ◽  
Size Dependent ◽  
The Earth ◽  
Dependent Viscosity

scholarly journals Modified Continuum Mechanics Modeling on Size-Dependent Properties of Piezoelectric Nanomaterials: A Review

Nanomaterials ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 27 ◽  
Author(s):  
Zhi Yan ◽  
Liying Jiang
Keyword(s):  
Continuum Mechanics ◽  
Size Dependent

Stone pavements in arid environments: Reasons for De overdispersion and grain-size dependent OSL ages

2019 ◽  
Vol 49 ◽  
pp. 191-198 ◽  
Author(s):  
M. Fuchs ◽  
J. Lomax
Keyword(s):  
Grain Size ◽  
Arid Environments ◽  
Size Dependent
Sign in / Sign up

Export Citation Format

Share Document