scholarly journals Grain Boundary Migration and the Texture of Films

1991 ◽  
Vol 13 (2-3) ◽  
pp. 91-99 ◽  
Author(s):  
Idajean M. Fisher ◽  
David A. Smith

Extensive studies of the microstructure of deposited films establish that grain boundary migration is a ubiquitous process in the development of microstructure and frequently the key process in the formation of a preferred orientation. This conclusion is supported by the interpretation of observations of the structure and orientation of films as a function of substrate temperature and post deposition annealing. Epitaxial deposits can result from oriented nucleation or selective growth processes. On amorphous substrates the anisotropy of the interfacial energies of the deposit results in a fiber texture at temperatures when grain growth occurs either during deposition or in a post-deposition anneal.

2007 ◽  
Vol 558-559 ◽  
pp. 551-556 ◽  
Author(s):  
Kazuto Okayasu ◽  
Hiroki Takekoshi ◽  
Hiroshi Fukutomi

Uniaxial compression deformation is conducted on solid solution Al-3mass%Mg and Al-3mass%Mg-0.2mass%Sc with Al3Sc precipitates in the strain rates ranging from 1.0×10-4s-1 to 5.0×10-3s-1 at 723K. High temperature yielding is observed. Fiber texture is constructed in all the deformation conditions. While the main component of the fiber texture changes from {011} to {001} in Al-3mass%Mg alloy with an increase in strain rate, no big change in texture main component is seen for Al-3mass%Mg-0.2mass%Sc alloy with Al3Sc precipitates. It is experimentally shown that the development of {001} fiber texture can be attributed to the grain boundary migration.


1969 ◽  
Vol 37 (286) ◽  
pp. 238-240 ◽  
Author(s):  
Donal M. Ragan

SummaryMosaic olivine textures, with straight triple grain boundaries meeting at angles of 120°, are common in dunites. This is a well-known feature of annealed metals, and is the result of grain-boundary migration during recrystallization in which the system tends toward a state of minimum interfacial energies. Geometrically similar textures are present at the boundaries between such mosaic grains and strain-banded relict olivine grains. The unstrained mosaic grains make angular projections into the strained grains exactly at the junctions between the deformation bands. These are interpreted to be triple junctions with the two differently oriented bands acting as separate grains, and thus also due to recrystallization.


Author(s):  
D. B. Williams ◽  
A. D. Romig

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).


Author(s):  
K. Vasudevan ◽  
H. P. Kao ◽  
C. R. Brooks ◽  
E. E. Stansbury

The Ni4Mo alloy has a short-range ordered fee structure (α) above 868°C, but transforms below this temperature to an ordered bet structure (β) by rearrangement of atoms on the fee lattice. The disordered α, retained by rapid cooling, can be ordered by appropriate aging below 868°C. Initially, very fine β domains in six different but crystallographically related variants form and grow in size on further aging. However, in the temperature range 600-775°C, a coarsening reaction begins at the former α grain boundaries and the alloy also coarsens by this mechanism. The purpose of this paper is to report on TEM observations showing the characteristics of this grain boundary reaction.


Anales AFA ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 47-51
Author(s):  
P.I. Achával ◽  
C. L. Di Prinzio

In this paper the migration of a grain triple junction in apure ice sample with bubbles at -5°C was studied for almost 3hs. This allowed tracking the progress of the Grain Boundary (BG) and its interaction with the bubbles. The evolution of the grain triple junction was recorded from successive photographs obtained witha LEICA® optical microscope. Simultaneously, numerical simulations were carried out using Monte Carlo to obtain some physical parameters characteristic of the BG migration on ice.


2021 ◽  
pp. 1-9
Author(s):  
Suo Saruwatari ◽  
Takahiro Kamo ◽  
Yuki Nakata ◽  
Kota Kadoi ◽  
Hiroshige Inoue

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