In situ investigation of liquid Ga penetration in Al bicrystal grain boundaries: grain boundary wetting or liquid metal embrittlement?

2005 ◽  
Vol 53 (1) ◽  
pp. 151-162 ◽  
Author(s):  
W. Ludwig ◽  
E. Pereiro-López ◽  
D. Bellet
Keyword(s):  
Liquid Metal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Liquid Metal Embrittlement ◽  
In Situ Investigation ◽  
Grain Boundary Wetting

The Formation of Liquid Metal Channels Network under Grain Boundary Wetting in the Cu-Bi System

2012 ◽  
Vol 323-325 ◽  
pp. 177-181
Author(s):  
A. A. Novikov ◽  
A.L. Petelin ◽  
Boris S. Bokstein ◽  
S. N. Zhevnenko ◽  
D. I. Orelkina
Keyword(s):  
Liquid Metal ◽  
Grain Boundary ◽  
Network Formation ◽  
Solid Metal ◽  
Triple Junctions ◽  
Liquid Bismuth ◽  
Grain Boundary Wetting ◽  
Penetration Depths ◽  
Effective Penetration

Grain boundary liquid grooving process takes place during the contact of solid metal phase with the metal melt. The liquid bismuth network formation along grain boundaries (GB) and triple junctions (TJ) was investigated in copper polycrystalline samples. The experimental observation in situ technique of Bi penetration through the Cu plate was used. Microscopic images of the liquid channels network were obtained. The temperature dependencies of GB and TJ effective penetration depths were determined. The effect of the GB and TJ diffusion on the liquid channels growth mechanism was discussed.

EFFECT OF SMALL BULK SULFUR CONTENT AND ANNEALING TEMPERATURE ON THE INTERGRANULAR FRACTURING SUSCEPTIBILITY OF METALLIC NICKEL

2016 ◽  
Vol 23 (06) ◽  
pp. 1650050 ◽  
Author(s):  
BOUTASSOUNA DJAMAL ◽  
RENÉ LE GALL ◽  
IBEN KHALDOUN LEFKAIER
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Sulfur Content ◽  
Auger Spectroscopy ◽  
Metallic Nickel ◽  
Boundary Equilibrium ◽  
Influence Of Temperature On ◽  
Sulfide Compound ◽  
Equilibrium Segregation

In this paper, we investigate the influence of temperature on the nickel grain boundary equilibrium segregation of sulfur and the resulting intergranular fracturing susceptibility. Auger electron spectroscopy has been used to study equilibrium segregation of sulfur to the grain boundaries of a metallic nickel, with a mass bulk content of 3.6[Formula: see text]ppm in sulfur. Samples were first annealed at adequate temperatures for sufficiently large equilibrium time, and then quenched in water at room temperature. The analysis carried out shows a significant increase of sulfur concentration in the grain boundary with decreasing temperature. However, the sulfur content in the grain boundary shows a drastic shrink at 700[Formula: see text]C. This can be interpreted by the formation of an aggregate sulfide compound in the area of the grain boundaries. At 650[Formula: see text]C, in situ brittle fracture becomes unworkable and only intragranular fractures are observed. Using the results obtained through the investigation of the grain boundaries by Auger spectroscopy, the standard segregation energy is estimated as [Formula: see text].

X-Ray Reflectivity Study of Single- and Bicrystals of Gold

1990 ◽  
Vol 208 ◽  
Author(s):  
M. R. Fitzsimmons ◽  
E. Burkel ◽  
J. Peisl
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Diffuse Scattering ◽  
Direct Evidence ◽  
X Ray ◽  
Specular Reflectivity ◽  
Boundary Measurements

ABSTRACTX-ray reflectivity techniques have been used to characterize the surfaces of 0.4µm thick Au films epitaxially grown on single-crystals of NaCl. Measurements of both the specular and non-specular reflectivity suggest that the Au surface is very rough. The nonspecular reflectivity provides valuable information about the correlation of the heights at different points on the surface. The first in situ reflectivity study of the formation and destruction of a grain boundary shows direct evidence for the existence of diffuse scattering from the grain boundary. Measurements of several [0011 twist grain boundaries suggest that the roughness and texture of an interface depends upon the geometrical orientation of the surrounding substrates.

In Situ EBSP Observations of Recrystallization in Commercial Purity Aluminum

2007 ◽  
Vol 558-559 ◽  
pp. 223-228 ◽  
Author(s):  
Katsura Kajihara
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Early Stage ◽  
Boundary Motion ◽  
Commercial Purity ◽  
Solute Content ◽  
In Situ Observations ◽  
Commercial Purity Aluminum ◽  
Grain Boundary Motion

This study presents in-situ EBSP observations of recrystallization in commercial purity aluminum sheets with different concentrations of solutes and different states of precipitation. The in-situ observations demonstrate clearly the behaviors of the nucleation and growth of recrystallized grains, and the movements of grain boundaries at an early stage of recrystallization. The high mobility of grain boundaries neighboring the deformed matrix was generally observed presumably due to strain-induced grain boundaries migration. The grain boundary motion was also found to strongly depend to the solute content level. These in-situ observations provide important evidence to show that the behaviors of grain boundary motion at an early stage of recrystallization leads to the grain size distribution and the curvature of grain boundaries after the primary recrystallization.

The Effect of Grain Boundaries on Surface Diffusion Mediated-Planarization of Polycrystalline Cu Films

1995 ◽  
Vol 389 ◽  
Author(s):  
R.A. Brain ◽  
D.S. Gardner ◽  
D.B. Fraser ◽  
H.A. Atwater
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Surface Diffusion ◽  
Cross Sections ◽  
Boundary Surface ◽  
Surface Profile ◽  
Transmission Electron Micrograph ◽  
Cu Films ◽  
Transmission Electron

ABSTRACTIn situ, ultrahigh vacuum anneals were performed to induce Cu reflow at 500°C following deposition of Cu films and a Ta barrier layer on 1 μm wide by 1 μm deep trenches. Transmission electron micrograph cross-sections show profiles which suggest that grain boundaries and surface energy anisotropy significantly affect reflow. The extent of reflow is dependent on the structure of grain boundary-surface intersections, and the surface profile consists of regions of low curvature within grains and with sharp discontinuities in curvature at grain boundaries, a structure that inhibits surface diffusion. We present results showing how the surface diffusion mediated reflow varies with grain boundary groove angle and position, and compare these results with finite-element simulations that model surface diffusion-driven reflow.

Effect of boron on the mechanism of strain transfer across grain boundaries in Ni3Al

1987 ◽  
Vol 2 (4) ◽  
pp. 436-440 ◽  
Author(s):  
G. M. Bond ◽  
I. M. Robertson ◽  
H. K. Birnbaum
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Dislocation Motion ◽  
Strain Transfer ◽  
Undoped Material ◽  
Sudden Failure ◽  
Transmission Electron ◽  
Large Numbers ◽  
Dislocation Sources

The effect of boron on the mechanism of strain transfer across grain boundaries in Ni3Al has been investigated by dynamic recording of events occurring during in-situ straining in the transmission electron microscope. Boundaries in both doped and undoped material can act as effective barriers to dislocation motion, large numbers of dislocations being incorporated into the boundary without any plastic strain occurring in the adjacent grain. In the undoped material, the grain-boundary strain is relieved by the sudden failure of the grain boundary. In the doped material the strain is relieved by the sudden generation and emission of large numbers of dislocations from the grain boundary. This effect may be understood by boron either increasing the grain-boundary cohesion or reducing the stress required to operate grain-boundary dislocation sources, rather than easing the passage of slip dislocations through the grain boundary.

Grain Boundary Complexion Transitions

2020 ◽  
Vol 50 (1) ◽  
pp. 465-492 ◽  
Author(s):  
Patrick R. Cantwell ◽  
Timofey Frolov ◽  
Timothy J. Rupert ◽  
Amanda R. Krause ◽  
Christopher J. Marvel ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Bulk Composition ◽  
Polycrystalline Metals ◽  
Research Challenges ◽  
Rapid Changes ◽  
And Performance ◽  
Property Changes ◽  
Processing Properties

Grain boundaries can undergo phase-like transitions, called complexion transitions, in which their structure, composition, and properties change discontinuously as temperature, bulk composition, and other parameters are varied. Grain boundary complexion transitions can lead to rapid changes in the macroscopic properties of polycrystalline metals and ceramics and are responsible for a variety of materials phenomena as diverse as activated sintering and liquid-metal embrittlement. The property changes caused by grain boundary complexion transitions can be beneficial or detrimental. Grain boundary complexion engineering exploits beneficial complexion transitions to improve the processing, properties, and performance of materials. Here, we review the thermodynamic fundamentals of grain boundary complexion transitions, highlight the strongest experimental and computationalevidence for these transitions, clarify a number of important misconceptions, discuss the advantages of grain boundary complexion engineering, and summarize existing research challenges.

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