Atomistic simulations on intergranular fracture toughness of copper bicrystals with symmetric tilt grain boundaries

2018 ◽  
Vol 24 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Cheng Bin Cui ◽  
Hyeon Gyu Beom
2010 ◽  
Vol 445 ◽  
pp. 39-42 ◽  
Author(s):  
Takashi Oyama ◽  
Nobuyuki Wada ◽  
Hiroshi Takagi

The role of grain boundaries (GBs) in the diffusion of oxygen vacancies (VO••s) in barium titanate (BaTiO3) and its mechanism were investigated using atomistic simulation techniques. It was found that GBs trapped VO••s at specific sites in the course of the diffusion, and the excess energy reflecting structural distortion of the GB was closely related to the availability of the trapping. GBs therefore act as a resistance of the diffusion of VO••s, suggesting that electrical degradation of multilayer ceramic capacitors (MLCCs), which is derived from vacancy diffusion, enables to be additionally improved by controlling GB structures in BaTiO3-based dielectrics.


1986 ◽  
Vol 81 ◽  
Author(s):  
S. P. Chen ◽  
A. F. Voter ◽  
D. J. Srolovitz

AbstractWe report a systematic atomistic simulation study of [001] symmetric tilt grain boundaries (GB) in Ni3Al, Ni, and Al. We found that the grain boundary energies and cohesive energies of Ni3Al and pure fcc Ni are approximately thesame. Grain boundary energies aid cohesive energies in Ni3Al depends stronglyon the grain boundary composition. The Al-rich boundaries have highest grain boundary energies and lowest cohesive energies. This offers an explanation for the stoichiometric effect on the boron ductilization


2018 ◽  
Vol 382 (35) ◽  
pp. 2464-2469 ◽  
Author(s):  
H.Y. Song ◽  
C.F. Li ◽  
S.F. Geng ◽  
M.R. An ◽  
M.X. Xiao ◽  
...  

2019 ◽  
Vol 21 (24) ◽  
pp. 13116-13125 ◽  
Author(s):  
Bharat Bhushan Sharma ◽  
Avinash Parashar

The aim of this research article was to investigate the effect of grain boundaries (GBs), and hydrogen functionalisation on the fracture toughness of bi-crystalline hexagonal boron nitride (h-BN) nanosheets.


2020 ◽  
Vol 326 ◽  
pp. 04006
Author(s):  
Benjamin T. Wilson ◽  
Joseph D. Robson ◽  
Christopher P. Race

The effects of H segregation to a Σ11 symmetric tilt Al grain boundary are investigated using atomistic simulations, as part of a wider study on cracking in 7xxx series alloys. Density functional theory based simulations of uniaxial straining of grain boundaries containing 11 different concentrations of H were performed under the cohesive zone fracture mechanics framework. The theoretical strength of grain boundaries is shown to be supressed by H segregation, and the cause of this is attributed to the prevention of the formation of Al ligaments across grain boundaries. Segregated concentrations of relevant alloying elements (Zn, Mg, and Cu) show minimal impact on the H embrittlement process investigated, namely H enhanced decohesion (HEDE). Further modelling, of H transport and grain boundary precipitates, is required to confirm the validity of the HEDE mechanism in the case of 7xxx alloys.


Author(s):  
R. W. Fonda ◽  
D. E. Luzzi

The properties of polycrystalline materials are strongly dependant upon the strength of internal boundaries. Segregation of solute to the grain boundaries can adversely affect this strength. In copper alloys, segregation of either bismuth or antimony to the grain boundary will embrittle the alloy by facilitating intergranular fracture. Very small quantities of bismuth in copper have long been known to cause severe grain boundary embrittlement of the alloy. The effect of antimony is much less pronounced and is observed primarily at lower temperatures. Even though moderate amounts of antimony are fully soluble in copper, concentrations down to 0.14% can cause grain boundary embrittlement.


Author(s):  
Zihui Zhao ◽  
Yafei Wang ◽  
Changguo Wang

This study investigated dynamic surface wrinkle propagation across a series of flower-like rotational grain boundaries (GBs) in graphene using theoretical solutions and atomistic simulations. It was found that there was...


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