Precipitation on grain boundaries in Al-Mg-Si alloys: The role of grain boundary misorientation

2022 ◽  
pp. 114494
Author(s):  
Zhijun Zhang ◽  
N.C. Parson ◽  
W.J. Poole
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Misorientation ◽  
Grain Boundary Misorientation

Measurement of solute segregation to grain boundaries in the AEM: A review

1988 ◽  
Vol 46 ◽  
pp. 606-607
Author(s):  
D. B. Williams ◽  
A. D. Romig
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Boundary Misorientation ◽  
Collector Plate ◽  
Segregation Process ◽  
Grain Boundary Misorientation ◽  
Structure Boundary ◽  
Equilibrium Segregation

The segregation of solute or imparity elements to grain boundaries can occur by three well-defined processes. The first is Gibbsian segregation in which an element of minimal matrix solubility confines itself to a monolayer at the grain boundary. Classical examples include Bi in Cu and S or P in Fe. The second process involves the depletion of excess matrix solute by volume diffusion to the boundary. In the boundary, the solute atoms diffuse rapidly to precipitates, causing them to grow by the ‘collector-plate mechanism.’ Such grain boundary diffusion is thought to initiate “Diffusion-Induced Grain Boundary Migration,” (DIGM). This process has been proposed as the origin of eutectoid transformations or discontinuous grain boundary reactions. The third segregation process is non-equilibrium segregation which result in a solute build-up around the boundary because of solute-vacancy interactions.All of these segregation phenomena usually occur on a sub-micron scale and are often affected by the nature of the grain boundary (misorientation, defect structure, boundary plane).

Characterization of Zinalco Alloy Superplastically Deformed Using Orientation Imaging Microscopy

2009 ◽  
Vol 1242 ◽  
Author(s):  
Ramos A. Mitsuo ◽  
Martínez F. Elizabeth ◽  
Negrete S. Jesús ◽  
Torres-Villaseñor G.
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Superplastic Deformation ◽  
Orientation Imaging Microscopy ◽  
Grain Boundary Sliding ◽  
Boundary Misorientation ◽  
Average Grain Size ◽  
Grain Boundary Misorientation ◽  
Misorientation Angles

ABSTRACTZinalco alloy (Zn-21mass%Al-2mass%Cu) specimens were deformed superplastically with a strain rate (ε) of 1×10-3 s-1 at homologous temperature (TH) of 0.68 (5 ). It was observed neck formation that indicate nonhomegeneus deformation. Grain size and grain boundaries misorientation changes, due superplastic deformation, were characterized by Orientation Imagining Microscopy (OIM) technique. It was studied three regions in deformed specimens and the results were compared with the results for a specimen without deformation. Average grain size of 1 mm was observed in non-deformed specimen and a fraction of 82% for grain boundary misorientation angles with a grain boundaries angles between 15° and 55° was found. For deformed specimen, the fraction of angles between 15° and 55° was decreced to average value of 75% and fractions of low angle (<5°) and high angle (>55°) misorientations were 10% and 15% respectively. The grain size and high fraction of grain boundary misorientation angles between 15° and 55° observed in the alloy without deformation, are favorable for grain rotation and grain boundary sliding (GBS) procces. The changes observed in the fraction of favorable grain boundary angles during superplastic deformation, shown that the superplastic capacity of Zinalco was reduced with the deformation.

Variant Selection in Fcc-to-Bcc Precipitation at Grain Boundaries in Ni-43Cr Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 305-308 ◽  
Author(s):  
Yoshitaka Adachi ◽  
Fu Xing Yin ◽  
Kazunari Hakata ◽  
Kaneaki Tsuzaki
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Tilt Angle ◽  
Boundary Plane ◽  
Variant Selection ◽  
Orientation Relationships ◽  
Boundary Misorientation ◽  
Grain Boundary Plane ◽  
Grain Boundary Misorientation ◽  
Selection Of

Variant selection of bcc-Cr at the grain boundaries in a supersaturated fcc matrix was studied using a Ni-43Cr alloy. The preferentially selected variant was examined as a function of the grain boundary misorientation, the tilt angle between the {111}fcc plane and the grain boundary plane, and the orientation relationships with respect to both of the adjacent matrix grains.

An atomistic simulation study of nanoscale sintering: The role of grain boundary misorientation

2019 ◽  
Vol 165 ◽  
pp. 180-189 ◽  
Author(s):  
Jesse M. Sestito ◽  
Fadi Abdeljawad ◽  
Tequila A.L. Harris ◽  
Yan Wang ◽  
Allen Roach
Keyword(s):  
Grain Boundary ◽  
Simulation Study ◽  
Atomistic Simulation ◽  
Boundary Misorientation ◽  
Grain Boundary Misorientation

scholarly journals Influence of multiaxial cyclic plastic loading on grain boundary misorientation profile in austenitic stainless steel

2019 ◽  
Vol 300 ◽  
pp. 08007
Author(s):  
Rima Dey ◽  
Soumitra Tarafder ◽  
S Sivaprasad
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Multiaxial Loading ◽  
Loading Conditions ◽  
Load Path ◽  
Boundary Misorientation ◽  
Proportional Loading ◽  
Dominant Mechanism ◽  
Load Paths ◽  
Grain Boundary Misorientation

304LN stainless was subjected to multiaxial loading employing different waveforms and load paths. The grain boundary misorientation profile so obtained post deformation was compared across loading conditions. It was found that the uniaxial and proportional conditions of loading result in more of twins, contrary to non-proportional loading conditions that resulted in substantially higher low angle grain boundaries. Also, under non-proportional loading the trapezoidal load path resulted in remarkably altered distribution of the grain boundaries compared to its contemporaries. Predominant martensitic transformation was found to be dominant mechanism of deformation for trapezoidal loading that also contributed to the altered misorientation profile.

Influence of Grain Boundary Structure on Liquid Metal Penetration Behavior

1999 ◽  
Vol 578 ◽  
Author(s):  
Liping Ren ◽  
D.F. Bahr ◽  
R.G. Hoagland
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Simulation Method ◽  
High Energy ◽  
Boundary Structure ◽  
Boundary Misorientation ◽  
Kikuchi Pattern ◽  
Grain Boundary Structure ◽  
Grain Boundary Misorientation ◽  
Penetration Behavior

AbstractThe penetration of Ga along Al grain boundaries under stress-free conditions is investigated in the present study. In-situ SEM observations indicate that the penetration rate of Ga along Al grain boundaries at room temperature ranged from 6.4 to 9.2 μm/s, which is similar to the rate of diffusion in the liquid state. For a specific high energy grain boundary, the grain boundary misorientation is determined from the TEM diffraction Kikuchi pattern, and a molecular statics simulation method was employed to investigate grain boundary structure. A comparison of the structure of this high energy boundary is made with the Σ11(131)[101] tilt grain boundary that is not penetrated by Ga in the absence of the applied stress. The results indicate that the grain boundary plane void structure in the high energy grain boundary may provide void channels for Ga monolayer penetration. In addition, penetration behavior investigated under different length scales supports this model.

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