Cubic spline elements for modelling microstructural evolution of materials controlled by solid-state diffusion and grain-boundary migration

2004 ◽  
Vol 196 (2) ◽  
pp. 724-750 ◽  
Author(s):  
H.N. Ch'ng ◽  
J. Pan
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Microstructural Evolution ◽  
Boundary Migration ◽  
Cubic Spline ◽  
Solid State Diffusion ◽  
Grain Boundary Migration ◽  
State Diffusion

Formation Mechanism of Diffusion Welded Joint

2011 ◽  
Vol 228-229 ◽  
pp. 666-671 ◽  
Author(s):  
Ho Sung Lee ◽  
Jong Hoon Yoon ◽  
Woo Hyun Cho
Keyword(s):  
Formation Mechanism ◽  
Welded Joint ◽  
Boundary Migration ◽  
Welding Process ◽  
Diffusion Welding ◽  
Solid State Diffusion ◽  
Grain Boundary Migration ◽  
Void Closure ◽  
Inert Environment ◽  
State Diffusion

In this study, solid state diffusion welding behavior of titanium alloys was investigated. Formation mechanism of diffusion welding process in six stages is proposed, which is based on cavitation process. The specimens were diffusion welded at elevated temperature under a hydrostatic pressure in an inert environment and the results confirmed the formation mechanism at each corresponding stage. This includes clear evidence of void closure and grain boundary migration at the final stage.

Exafs Studies of Grain Boundary Diffusion and Segregation

1986 ◽  
Vol 77 ◽  
Author(s):  
S. M. Heald ◽  
H. Chen ◽  
J. M. Tranquada
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Diffusion ◽  
Structural Information ◽  
Solid State Diffusion ◽  
Interface Reactions ◽  
Tin Bronze ◽  
State Diffusion

ABSTRACTThe dominant pathway for thin film interdiffusion and interface reactions is often via grain boundaries. We have made EXAFS measurements of grain boundary constituents for two systems: interdiffusion in Ag-Au bilay-ers and solid state reaction of Nb with a copper-tin bronze to form Nb3Sn. The Ag-Au results indicate that Au in saturated Ag grain boundaries has an environment similar to a dilute Au in Ag solution with reduced coordination. For the Nb-bronze reaction, the results for the Cu environment indicate distinct changes in the grain boundary environment when small amounts of Ti, Hf, Zr, and Ta are added to the starting Nb. Both results demonstrate the ability of EXAFS to probe grain boundary environments, and to provide important structural information in understanding solid state diffusion and interdiffusion in thin film systems.

Rate and Driving Forces of Grain-Boundary Migration in Solid-State Alloys

2021 ◽  
Vol 1022 ◽  
pp. 218-223
Author(s):  
V.S. Novosadov ◽  
R.Kh. Dadashev ◽  
D.Z. Elimkhanov ◽  
R.S. Dzhambulatov
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Driving Forces ◽  
Boundary Migration ◽  
Physical And Mechanical Properties ◽  
Grain Boundary Migration ◽  
Liquid Phases ◽  
Brazed Joints ◽  
First Time ◽  
Effect Of Surface

Based on the interaction of solid and liquid phases in metallic systems, the paper deals with the properties of grain boundary propagation (migration) in solid-state alloys. Using the effect of surface solid-state dispersion enables to obtain composite materials and brazed joints with a required set of physical and mechanical properties. For the first time, the authors investigate the features of boundary migration in type II systems, in which, in accordance with the thermodynamic criterion σss< 2 σSL, the grain-boundary propagation is not basically allowed.

scholarly journals Applications of Ab Initio Modeling to Materials Science: Grain Boundary Cohesion and Solid State Diffusion

2004 ◽  
Author(s):  
GA Young ◽  
R Najafabadi ◽  
W Strohmayer ◽  
J Vollmer ◽  
C Thompson ◽  
...  
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Ab Initio ◽  
Materials Science ◽  
Solid State Diffusion ◽  
Ab Initio Modeling ◽  
State Diffusion

Diffusion at Short Circuits: State of the Art

2010 ◽  
Vol 297-301 ◽  
pp. 1267-1283 ◽  
Author(s):  
Boris S. Bokstein
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Boundary Diffusion ◽  
Boundary Segregation ◽  
Grain Boundary Diffusion ◽  
Polycrystalline Materials ◽  
Solid State Diffusion ◽  
Diffusion Parameters ◽  
State Diffusion ◽  
Fisher Model

Evidence for solid-state diffusion (the second half of the 19th century). The first measurements of solid state diffusion (W. Roberts-Austen, 1896–1922). The first tracer experiments to determine the solid-state diffusion (G. von Hevesy, 1913–1923). The first evidence of accelerated diffusion in polycrystalline materials (1924–1935). Autoradiographic studies of grain boundary diffusion (50s of 20th century). The first quantitative experimental and theoretical studies of the “short circuiting” diffusion (beginning from 1949, D. Turnbull and R. Hoffman – General Electric Research Lab.): radiotracer serial sectioning method, the Fisher model (1951) for grain boundary diffusion, exact solutions and developments of the Fisher model (1954–1963). The progress in the experimental methods for determination of grain boundary diffusion data and results of measurements for different metallic systems (up to date). The measurements of grain boundary diffusion parameters in the B and C regimes. Grain boundary diffusion and grain boundary segregation. Nonlinear segregation effects. Structural effects of grain boundary diffusion. Diffusion in bicrystals. Diffusion in nanocrystals. Computer simulation of grain boundary diffusion. Mechanisms of grain boundary diffusion.

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).

Domain coarsening by grain boundary migration in ordered Ni4Mo

1986 ◽  
Vol 44 ◽  
pp. 560-561
Author(s):  
K. Vasudevan ◽  
H. P. Kao ◽  
C. R. Brooks ◽  
E. E. Stansbury
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Short Range ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Rapid Cooling ◽  
Temperature Range ◽  
Fee Structure ◽  
Domain Coarsening ◽  
Boundary Reaction

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.

STUDY OF THE GRAIN BOUNDARY MIGRATION IN A TRICRISTAL PURE ICE WITH BUBBLES

Anales AFA ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 47-51
Author(s):  
P.I. Achával ◽  
C. L. Di Prinzio
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Numerical Simulations ◽  
Triple Junction ◽  
Boundary Migration ◽  
Optical Microscope ◽  
Physical Parameters ◽  
Grain Boundary Migration

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.

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