scholarly journals The Role of Grain Boundary Diffusion in the Solute Drag Effect

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2348
Author(s):  
R. K. Koju ◽  
Y. Mishin

Molecular dynamics (MD) simulations are applied to study solute drag by curvature-driven grain boundaries (GBs) in Cu–Ag solid solution. Although lattice diffusion is frozen on the MD timescale, the GB significantly accelerates the solute diffusion and alters the state of short-range order in lattice regions swept by its motion. The accelerated diffusion produces a nonuniform redistribution of the solute atoms in the form of GB clusters enhancing the solute drag by the Zener pinning mechanism. This finding points to an important role of lateral GB diffusion in the solute drag effect. A 1.5 at.%Ag alloying reduces the GB free energy by 10–20% while reducing the GB mobility coefficients by more than an order of magnitude. Given the greater impact of alloying on the GB mobility than on the capillary driving force, kinetic stabilization of nanomaterials against grain growth is likely to be more effective than thermodynamic stabilization aiming to reduce the GB free energy.

2017 ◽  
Vol 18 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Naoto Fujiyama ◽  
Toshinobu Nishibata ◽  
Akira Seki ◽  
Hiroyuki Hirata ◽  
Kazuhiro Kojima ◽  
...  

2021 ◽  
Vol 1016 ◽  
pp. 832-839
Author(s):  
Beatriz López ◽  
Beatriz Pereda ◽  
Felipe Bastos ◽  
J.M. Rodriguez-Ibabe

The aim of this work is to investigate the dissolution behavior of Nb in hot charging hot rolling configurations. To do so, an indirect experimental procedure is used to quantify the amount of Nb present in solution before rolling. The method is based on the effect of dissolved Nb on static recrystallization kinetics due to its solute drag effect. After different thermal cycles, simulating cold and hot charging conditions, double hit torsion tests have been performed with a 0.23%C steel microalloyed with 0.03% Nb. By means of these tests, the static softening behavior has been determined. Comparison of the recrystallization times allows indirect evaluation of the amount of Nb in solid solution after each treatment. The results have been correlated with the precipitation state of the samples.


1983 ◽  
Vol 23 ◽  
Author(s):  
Michael J. Aziz

ABSTRACTA simple model for solute trapping during rapid solidification is presented in terms of a single unknown parameter, the interfacial diffusivity Di. A transition from equilibrium segregation to complete solute trapping occurs over roughly an order of magnitude in growth speed, as the interface speed surpasses the maximum speed with which solute atoms can diffuse across the interface to remain ahead of the growing crystal. This diffusive speed is given by Di/λ, where λ is the interatomic spacing, and is typically of the order 10 meters per second. Comparison is made with experiment. The steady–state speed of a planar interface is predicted by calculating the free energy dissipated by irreversible processes at the interface and equating it to the available driving free energy. A solute drag term and an intrinsic interfacial mobility term are included in the dissipation calculations. Steady–state solutions are presented for Bi–doped Si during pulsed laser annealing.


1998 ◽  
Vol 29 (13) ◽  
pp. 1029-1034 ◽  
Author(s):  
Masayoshi Suehiro ◽  
Zi-Kui Liu ◽  
John Ågren

1990 ◽  
Vol 24 (9) ◽  
pp. 1831-1835 ◽  
Author(s):  
Y.J.M. Brechet ◽  
G.R. Purdy

2019 ◽  
Vol 177 ◽  
pp. 187-197 ◽  
Author(s):  
Goro Miyamoto ◽  
Kentaro Yokoyama ◽  
Tadashi Furuhara

2012 ◽  
Vol 44 (8) ◽  
pp. 3472-3483 ◽  
Author(s):  
C. Qiu ◽  
H. S. Zurob ◽  
D. Panahi ◽  
Y. J. M. Brechet ◽  
G. R. Purdy ◽  
...  

2007 ◽  
Vol 558-559 ◽  
pp. 107-111 ◽  
Author(s):  
G.H. Akbari ◽  
H. Abbaszadeh ◽  
H. Ghotbi Ravandi

The effects of alloying elements and impurities on the microstructure and properties of metals and alloys are important. Understanding of these effects may help to control and produce products with desired properties at lower cost. In the present work the effects of Al, Si and Mn on the recrystallization behavior, hardness and microstructural changes of an Fe- containing brass during annealing were studied. The results show that alloying elements strongly affect recrystallization kinetics and resulted finer microstructures. Hardness variations during annealing are consistent with microstructural observations and the presence of alloying elements. All elements slow down recrystallization progress and increase resulted hardness values. The resulted microstructures in the presence of alloying elements are much finer than that of plain 70B brass. It was concluded that the present alloying elements affect the recrystallization behavior of 70B brass in a similar manner. Their mechanism of interactions is solute drag effect and their effects sum up when they present together.


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