scholarly journals Influence of Temperature on Mechanical Properties of Nanocrystalline 316L Stainless Steel Investigated via Molecular Dynamics Simulations

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2803 ◽  
Author(s):  
Abdelrahim Husain ◽  
Peiqing La ◽  
Yue Hongzheng ◽  
Sheng Jie
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Stainless Steel ◽  
Molecular Dynamics Simulations ◽  
Yield Stress ◽  
316L Stainless Steel ◽  
Deformation Mechanisms ◽  
Grain Sizes ◽  
Dynamics Simulations

Molecular dynamics simulations were conducted to study the mechanical properties of nanocrystalline 316L stainless steel under tensile load. The results revealed that the Young’s modulus increased with increasing grain size below the critical average grain size. Two grain size regions were identified in the plot of yield stress. In the first region, corresponding to grain sizes above 7.7 nm, the yield stress decreased with increasing grain size and the dominant deformation mechanisms were deformation twinning and extended dislocation. In the second region, corresponding to grain sizes below 7.7 nm, the yield stress decreased rapidly with decreasing grain size and the dominant deformation mechanisms were grain boundary sliding and also grain rotation. The yield strength and Young’s modulus were both found to decrease with increasing temperature, which increased the interatomic distance and thereby decreased the interatomic bonding force.

Grain-size dependence of mechanical properties in polycrystalline boron-nitride: a computational study

2015 ◽  
Vol 17 (34) ◽  
pp. 21894-21901 ◽  
Author(s):  
Matthew Becton ◽  
Xianqiao Wang
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Boron Nitride ◽  
Molecular Dynamics Simulations ◽  
Failure Mechanism ◽  
Size Dependence ◽  
Computational Study ◽  
Grain Sizes ◽  
Dynamics Simulations

Molecular dynamics simulations are performed to investigate the mechanical properties and failure mechanism of polycrystalline boron nitride sheet with various grain sizes.

Effects of temperature and grain size on deformation of polycrystalline copper–graphene nanolayered composites

2020 ◽  
Vol 22 (8) ◽  
pp. 4741-4748 ◽  
Author(s):  
Yunlong Ma ◽  
Sen Zhang ◽  
Yunfei Xu ◽  
Xiaoyi Liu ◽  
Sheng-Nian Luo
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Molecular Dynamics Simulations ◽  
Polycrystalline Copper ◽  
Mechanical Models ◽  
Effects Of Temperature ◽  
Dynamics Simulations

The effects of temperature and grain size on mechanical properties of polycrystalline copper–graphene nanolayered (PCuGNL) composites are investigated by analytical mechanical models and molecular dynamics simulations.

Nanograin size effects on deformation mechanisms and mechanical properties of nickel: A molecular dynamics study

2021 ◽  
Vol 11 (11) ◽  
pp. 1841-1855
Author(s):  
Alexandre Melhorance Barboza ◽  
Ivan Napoleão Bastos ◽  
Luis César Rodríguez Aliaga
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Stress Relaxation ◽  
Strain Rate ◽  
Grain Boundaries ◽  
Rate Sensitivity ◽  
Deformation Mechanisms ◽  
Triple Junctions ◽  
Grain Sizes

The grain size refinement of metallic materials to the nanometer scale produces interesting properties compared to the coarse-grained counterparts. Their mechanical behavior, however, cannot be explained by the classical deformation mechanisms. Using molecular dynamics simulations, the present work examines the influence of grain size on the deformation mechanisms and mechanical properties of nanocrystalline nickel. Samples with grain sizes from 3.2 to 24.1 nm were created using the Voronoi tessellation method and simulated in tensile and relaxation tests. The yield and ultimate tensile stresses follow an inverse Hall-Petch relationship for grain sizes below ca. 20 nm. For samples within the conventional Hall-Petch regime, no perfect dislocations were observed. Nonetheless, a few extended dislocations were nucleated from triple junctions, suggesting that the suppression of conventional slip mechanism is not uniquely responsible for the inverse Hall-Petch behavior. For samples respecting the inverse Hall-Petch regime, the high number of triple junctions and grain boundaries allowed grain rotation, grain boundary sliding, and diffusion-like behavior that act as competitive deformation mechanisms. For all samples, the atomic configuration analysis showed that Shockley partial dislocations are nucleated at grain boundaries, crossing the grain before being absorbed in opposite grain boundaries, leaving behind stacking faults. Interestingly, the stress relaxation tests showed that the strain rate sensitivity decreases with grain size for a specific grain size range, whereas for grains below approximately 10 nm, the strain rate sensitivity increases as observed experimentally. Repeated stress relaxation tests were also performed to obtain the effective activation volume parameter. However, the expected linear trend in pertinent plots required to obtain this parameter was not found.

Competing roles of interfaces and matrix grain size in the deformation and failure of polycrystalline Cu–graphene nanolayered composites under shear loading

2018 ◽  
Vol 20 (36) ◽  
pp. 23694-23701 ◽  
Author(s):  
Sen Zhang ◽  
Yunfei Xu ◽  
Xiaoyi Liu ◽  
Sheng-Nian Luo
Keyword(s):  
Molecular Dynamics ◽  
Grain Size ◽  
Molecular Dynamics Simulations ◽  
Analytical Model ◽  
Shear Behavior ◽  
Shear Loading ◽  
Deformation And Failure ◽  
Grain Sizes ◽  
Dynamics Simulations

The roles of interfaces and matrix grain size in the deformation and failure of polycrystalline Cu–graphene nanolayered (PCuGNL) composites under shear loading are explored with molecular dynamics simulations for different repeat layer spacings (λ), Cu grain sizes (D) and graphene chiralities, and an analytical model is proposed to describe the shear behavior.

scholarly journals Molecular dynamics simulations of mechanical failure in polymorphic arrangements of amyloid fibrils containing structural defects

2013 ◽  
Vol 4 ◽  
pp. 429-440 ◽  
Author(s):  
Hlengisizwe Ndlovu ◽  
Alison E Ashcroft ◽  
Sheena E Radford ◽  
Sarah A Harris
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Amyloid Fibrils ◽  
Amyloid Fibril ◽  
Steered Molecular Dynamics ◽  
Mechanical Failure ◽  
Structural Defects ◽  
Dynamics Simulations

We examine how the different steric packing arrangements found in amyloid fibril polymorphs can modulate their mechanical properties using steered molecular dynamics simulations. Our calculations demonstrate that for fibrils containing structural defects, their ability to resist force in a particular direction can be dominated by both the number and molecular details of the defects that are present. The simulations thereby suggest a hierarchy of factors that govern the mechanical resilience of fibrils, and illustrate the general principles that must be considered when quantifying the mechanical properties of amyloid fibres containing defects.

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