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2 edition of Effect of solute and orientation parameters on grain boundary motion found in the catalog.

Effect of solute and orientation parameters on grain boundary motion

Dionisyj Wasyl Demianczuk

# Effect of solute and orientation parameters on grain boundary motion

## by Dionisyj Wasyl Demianczuk

Published in [Toronto] .
Written in English

Subjects:
• Dislocations in metals,
• Grain boundaries

• Edition Notes

The Physical Object ID Numbers Contributions Toronto, Ont. University. Pagination 167 leaves. Number of Pages 167 Open Library OL19839527M

There is countervailing evidence, however, that suggests that solute drag provides a stronger influence on grain boundary mobility. This paper presents new evidence for a pronounced effect of solute based on experiments in which individual boundaries migrate under the driving pressure of stored energy from prior plastic strain. Grain boundaries are barriers to slip: Owing to misalignment of the slip planes in adjacent grains, a dislocation passing the grain boundary have to change its direction and thus lose its energy. A single grain may be favorably oriented for slip, but cannot deform until the adjacent grains (less favorable) are also capable to slip;.

The primary driving force for boundary motion was that of curvature of the grain boundaries themselves. Also, the similarity in grain orientation tends to minimize differences in strain energy from residual stresses in the foil. The nm thick Al films were deposited at a rate of nm/s by DC magnetron sputtering from % pure targets. velocity and stored energy, it is possible to calculate grain boundary mobility and correlate mobility with grain boundary misorientation. Grain boundary Mobility is a useful parameter to metallurgists as a predictor of grain size after deformation and heat treatments. However, grain.

For the case of solute atoms (impurities), the drag effect on grain boundary migration is influenced by the solute diffusivity within the lattice, the concentration of solute atoms at the grain. Solid solution hardening Parelastic interaction - lattice parameter effect Solute - both larger and smaller than the matrix - can find an energetically favorable place in a dislocation. The energy difference of the solute between a general lattice site and a site in the core of a dislocation becomes a barrier to dislocation motion.

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### Effect of solute and orientation parameters on grain boundary motion by Dionisyj Wasyl Demianczuk Download PDF EPUB FB2

From the measured grain boundary velocity the reduced boundary mobility (1) A≡va=A 0 exp − H kT =mσ, was determined, where H is the activation enthalpy of migration A 0 a preexponential factor and m the grain boundary mobility.

The latter is given by the ratio of velocity v and driving force p (2) m= v p = v σ/a. The reduced mobility 1 will be used in the following for sake of by: A grain boundary is the interface between two grains, or crystallites, in a polycrystalline boundaries are 2D defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material.

Most grain boundaries are preferred sites for the onset of corrosion and for the precipitation of new phases from the solid.

Atomic-scale simulations are performed to study the effect of solute segregation on the shear-induced motion of select grain boundaries in the classical $\alpha$-Fe/C system. Grain boundaries play an important role in dictating the mechanical and physical properties of nanocrystalline (NC) materials because of the increased volume fraction of intercrystalline components as the grain size decreases.

In general, grain boundaries have a high energy level and there exists a thermodynamic driving force to reduce the overall area of grain boundaries through grain Cited by: 4.

In-Situ Quantification of Solute Effects on Grain Boundary Mobility and Character in Aluminum Alloys During Recrystallization Article (PDF Available) in Materials Science Forum The effects of solute drag on grain growth kinetics were studied in two dimensional (2-D) computer simulations by using a diffuse-interface field model.

It is shown that, in the low velocity / low driving force regime, the velocity of a grain boundary motion departs from a linear relation with driving force (curvature) with solute drag. In these simulations, the () symmetric tilt grain boundary of β-Sn, with varying amounts of Ag or Cu solute particles randomly placed in interstitial positions along the interface, is modeled.

The () distinction indicates that two grains of β-Sn are rotated opposite to one another until they both share a common () Miller plane, equivalent to a ° twist boundary (Sutton and. Adapted solute drag model for impurity-controlled grain boundary motion Hao Sun and Chuang Denga) Department of Mechanical Engineering, University of Manitoba, Winnipeg, Manitoba R3T 5V6, Canada (Received 8 March ; accepted 11 June ) In this study, impurity segregation and solute drag effects on grain boundary (GB) motion were.

The effect of solute atoms on grain boundary migration cannot adequately be described by standard impurity drag theories. A more satisfactory agreement is obtained by taking an interaction of the impurities in the boundary into account.

The orientation dependence of grain boundary motion and the formation of recrystallization textures. The problem of the effect of impurities on grain boundary motion has received a good deal of theor­ to a coincidence boundary with orientation near that of the general boundary [5].

The range of the elastic lattice parameter area of grain boundary Burgers vector (30b) mole fraction of A. The role of entropy in materials science is demonstrated in this report in order to establish its importance for the example of solute segregation at the grain boundaries of bcc iron.

We show that substantial differences in grain boundary chemistry arise if their composition is calculated with or without consideration of the entropic term. @article{osti_, title = {Development of Computational Tools for Modeling Thermal and Radiation Effects on Grain Boundary Segregation and Precipitation in Fe-Cr-Ni-based Alloys}, author = {Yang, Ying}, abstractNote = {This work aims at developing computational tools for modeling thermal and radiation effects on solute segregation at grain boundaries (GBs) and precipitation.

Based on the last two effects, a method of prediction of segregation enthalpy and entropy is presented. Besides the effect of intensive variables to grain boundary segregation, it is shown that another parameter – grain size – can affect the grain boundary segregation mainly in case of nanosized grains.

@article{osti_, title = {Strain induced grain boundary migration effects on grain growth of an austenitic stainless steel during static and metadynamic recrystallization}, author = {Paggi, A., E-mail: [email protected] and Angella, G.

and Donnini, R.}, abstractNote = {Static and metadynamic recrystallization of an AISI L austenitic stainless steel was investigated at °C and. Because grains usually have varying crystallographic orientations, grain boundaries arise.

While undergoing deformation, slip motion will take place. Grain boundaries act as an impediment to dislocation motion for the following two reasons: 1. Dislocation must change its direction of motion due to the differing orientation of grains.

We use this potential to determine the physical parameters in the Cahn–Lücke–Stüwe (CLS) model for the effect of impurities on grain boundary mobility.

These include the heat of segregation of Fe to grain boundaries in Al and the diffusivity of Fe in Al. Journal of Biomimetics, Biomaterials and Biomedical Engineering Materials Science. Defect and Diffusion Forum. The usual effect of solute addition is to raise the yield stress and the level of stress‐strain curve as a whole.

Since solute atoms affect the entire stress‐strain curve, these atoms have more influence on the frictional resistance to the dislocation motion than on the static. inverted T’s distributed with or without impurity/solute-associated black circles, also with a left-side solute-associated subgrain boundary and right-side grain boundary region with distributed solute segregation.

The subgrain obstacle to s lip penetration is weaker than that presented by a grain boundary. Figure 2. Impurity effects on grain boundary migration M I Mendelev and D J Srolovitz-Atomistically informed solute drag in using the models in order to extract the model parameters [8–10].

One reason is that a direct we have instead focused on the relative kinetics of interface motion to solute motion (i.e.

solute diffusivity). We have also. INVESTIGATION INTO THE EFFECT OF SOLID SOLUTION CHEMISTRY ON LATTICE PARAMETERS This research aimed at investigating the changes in lattice parameters with increase in solute Grain boundary barrier to dislocation motion: slip plane discontinues or change orientation .grain growth rate.

The effectiveness of the solute drag effect is affected by an orientation dependence of the solute seg-regation to the boundary rather than an intrinsic structure dependence of grain boundary mobility. The grain boundary curvature is a main source of the driving force of grain boundary migration.

The P content may play a role. Grain boundaries (GBs) in polycrystalline materials have a significant influence on numerous material properties 1,2,3,4,5,6,7,8, boundary engineering (GBE) .