153 AFM Observation of the Local Deformation Field near the Grain Boundary of a Copper Bicrystal

2008 ◽  
Vol 2008.21 (0) ◽  
pp. 692-693
Author(s):  
Yoshikazu HIGA ◽  
Katsuyoshi NAKAMOTO
Keyword(s):  
Grain Boundary ◽  
Local Deformation ◽  
Deformation Field ◽  
Afm Observation

Novel Concept of Creep Strengthening Mechanism using Grain Boundary Fe2Nb Laves Phase in Austenitic Heat Resistant Steel

2011 ◽  
Vol 1295 ◽  
Author(s):  
Imanuel Tarigan ◽  
Keiichi Kurata ◽  
Naoki Takata ◽  
Takashi Matsuo ◽  
Masao Takeyama
Keyword(s):  
Grain Boundary ◽  
Strengthening Mechanism ◽  
Local Deformation ◽  
Creep Rupture ◽  
Laves Phase ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Term Creep

ABSTRACTThe creep behavior of a new type of austenitic heat-resistant steel Fe-20Cr-30Ni-2Nb (at.%), strengthened by intermetallic Fe2Nb Laves phase, has been examined. Particular attention has been given to the role of grain boundary Laves phase in the strengthening mechanism during long-term creep. The creep resistance increases with increasing area fraction (ρ) of grain boundary Laves phase according to equation ε/ε = (1−ρ), where ε0 is the creep rate at ρ = 0. In addition, the creep rupture life is also extended with increasing ρ without ductility loss, which can yield up to 77% of elongation even at ρ = 89%. Microstructure analysis revealed local deformation and well-developed subgrains formation near the grain boundary free from precipitates, while dislocation pile-ups were observed near the grain boundary Laves phase. Thus, the grain boundary Laves phase is effective in suppressing the local deformation by preventing dislocation motion, and thereby increases the long-term creep rupture strength. This novel creep strengthening mechanism was proposed as “grain boundary precipitation strengthening mechanism” (GBPS).

scholarly journals Approach to insect wing shape and deformation field measurement

2017 ◽  
Author(s):  
Duo Yin ◽  
Zhen Wei ◽  
Zeyu Wang
Keyword(s):  
Field Measurement ◽  
Local Deformation ◽  
Wing Shape ◽  
Deformation Field ◽  
Concentrated Force ◽  
Insect Wing ◽  
Summary Statement ◽  
Static Criterion ◽  
Stiffness Distribution ◽  
Better Than

Summary StatementA fine shape and deformation field measurement of insect wing is achieved by a self-developed setup. This measurement could foster investigation of insect wing stiffness distribution.AbstractFor measuring the shape and deformation of insect wing, a scanning setup adopting line laser and coaxial LED light is developed. Wing shape can be directly acquired from the line laser images by triangulation. Yet the wing deformation field can also be obtained by a self-devised algorithm that processes the images from line laser and coaxial LED simultaneously. During the experiment, three wing samples from termite and mosquito under concentrated force are scanned. The venation and corrugation could be significantly identified from shape measurement result. The deformation field is sufficiently accurate to demonstrate its variation from wing base to tip. The load conditions in experiments are also be discussed. For softer wings, local deformation is apparent if pinhead is employed to impose force. The similarity analysis is better than 5% deformation ratio as a static criterion, if the wing is simplified as a cantilever beam. The setup is proved to be effective and versatile. The shape and deformation fields would give enough details for the measurement of wing stiffness distribution.

scholarly journals Twinning-assisted dynamic adjustment of grain boundary mobility

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qishan Huang ◽  
Qi Zhu ◽  
Yingbin Chen ◽  
Mingyu Gong ◽  
Jixue Li ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Nanocrystalline Materials ◽  
High Performance ◽  
Practical Implication ◽  
Local Deformation ◽  
Dynamic Adjustment ◽  
Grain Boundary Mobility ◽  
Wide Range ◽  
Mechanical Behaviours ◽  
Dynamics Simulations

AbstractGrain boundary (GB) plasticity dominates the mechanical behaviours of nanocrystalline materials. Under mechanical loading, GB configuration and its local deformation geometry change dynamically with the deformation; the dynamic variation of GB deformability, however, remains largely elusive, especially regarding its relation with the frequently-observed GB-associated deformation twins in nanocrystalline materials. Attention here is focused on the GB dynamics in metallic nanocrystals, by means of well-designed in situ nanomechanical testing integrated with molecular dynamics simulations. GBs with low mobility are found to dynamically adjust their configurations and local deformation geometries via crystallographic twinning, which instantly changes the GB dynamics and enhances the GB mobility. This self-adjust twin-assisted GB dynamics is found common in a wide range of face-centred cubic nanocrystalline metals under different deformation conditions. These findings enrich our understanding of GB-mediated plasticity, especially the dynamic behaviour of GBs, and bear practical implication for developing high performance nanocrystalline materials through interface engineering.

scholarly journals Elastic Properties of Statistically Equivalent Materials With Varying Individual Grain Orientations

1995 ◽  
Vol 25 (1) ◽  
pp. 17-24 ◽  
Author(s):  
H. Kiewel ◽  
H. J. Bunge ◽  
L. Fritsche
Keyword(s):  
Elastic Properties ◽  
Displacement Field ◽  
Elastic Moduli ◽  
Local Deformation ◽  
Deformation Field ◽  
Copper Metal ◽  
Bcc Lattice ◽  
Real Material ◽  
Different Types ◽  
Grain Orientations

The elastic properties of copper metal with different individual grain orientations exhibiting the same texture are determined. We simulate the real material by two different types of clusters. The first one consists of 365 cubic grains, the second cluster is an arrangement of 181 Wigner-Seitz cells of a body centred cubic (bcc)-lattice. For each type of cluster we let the local grain orientations vary. The displacement field inside these aggregates as a result of a homogeneous deformation acting on the surface of the clusters is calculated. Although the resulting local deformation field for different individual grain orientations varies strongly, the macroscopic elastic moduli are in the frame of this simulation identical for any cluster of the same type, as it has to be for statistically equivalent materials.

303 Influence of local deformation at grain boundary on adhesion strength of the Cu/SiN interface in LSI interconnect

2014 ◽  
Vol 2014.63 (0) ◽  
pp. _303-1_-_303-2_
Author(s):  
Makoto HANAI ◽  
Nobuyuki SHISHIDO ◽  
Shoji KAMIYA ◽  
Hisashi SATO ◽  
Kozo KOIWA ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Adhesion Strength ◽  
Local Deformation

Dependence of Intergranular Fracture on Boundary Topography and Cohesion

1973 ◽  
Vol 31 ◽  
pp. 150-151
Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Boundary Shear ◽  
Room Temperature Ductility ◽  
Solid Solution Matrix ◽  
Nickel Base ◽  
Solution Matrix ◽  
Different Levels ◽  
Base Superalloy

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.

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