Molecular Dynamics Simulation of the Migration of Tilt Grain Boundaries in Ni and Ni{sub 3}Al

Journal Article · Tue Jan 15 04:00:00 EST 2019 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776118120087· OSTI ID:22917819

Zorya, I. V. ^[1]; Starostenkov, M. D. ^[2]; Rakitin, R. Yu. ^[3]; Tabakov, P. Ya. ^[4]

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1. Siberian State Industrial University (Russian Federation)
2. Polzunov Altai State Technical University (Russian Federation)
3. Altai State University (Russian Federation)
4. Durban University of Technology (South Africa)

The migration of the 〈100〉 and 〈111〉 tilt boundaries in Ni and the Ni{sub 3}Al intermetallic compound is studied by molecular dynamics simulation. The low-angle 〈100〉 boundaries in Ni and Ni{sub 3}Al are shown to migrate much more slowly (by approximately two times at a temperature of 1700 K) that the 〈111〉 boundaries, which is related to different migration mechanisms of the 〈100〉 and 〈111〉 boundaries. The migration of the 〈100〉 boundaries is found to occur by the splitting of paired grain-boundary dislocations followed by a change of partner dislocations, which proceeds via the slip of split dislocations. The 〈111〉 tilt boundaries move according to a combined action of the following two mechanisms: the mechanism described above and the mechanism consisting in joint slip of paired grain-boundary dislocations, which have common slip planes in contrast to the grain-boundary dislocations in 〈100〉 boundaries. Since the joint slip of paired dislocations has a relatively low activation energy, the mobility of the 〈111〉 tilt boundaries is higher than that of the 〈100〉 boundaries. Our molecular dynamics studies demonstrate that the migration rate of analogous boundaries in Ni{sub 3}Al is significantly lower than in Ni (by approximately three times at a temperature of 1700 K), which is partly caused by the additional energy consumed for the formation of a disordered region behind a migrating boundary in Ni{sub 3}Al. Because of a relatively low boundary mobility in Ni{sub 3}Al, the contribution of diffusion atomic displacements during boundary migration is higher as compared to Ni.

• OSTI ID: 22917819
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 1 Vol. 128; ISSN JTPHES; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
ALUMINIUM COMPOUNDS
ATOMIC DISPLACEMENTS
BINARY ALLOY SYSTEMS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
DIFFUSION
DISLOCATIONS
GRAIN BOUNDARIES
INTERMETALLIC COMPOUNDS
MOLECULAR DYNAMICS METHOD
NICKEL
NICKEL COMPOUNDS
SLIP
TEMPERATURE RANGE 1000-4000 K