Determination of vacancy mechanism for grain boundary self-diffusion by computer simulation

Technical Report · Mon Jun 01 04:00:00 EDT 1981

DOI:https://doi.org/10.2172/6470058· OSTI ID:6470058

Balluffi, R. W.; Kwok, T.; Bristowe, P. D.; Brokman, A.; Ho, P. S.; Yip, S.

It is currently well established that the fast self-diffusion which occurs along grain boundaries (GBs) in metals must occur by a point defect exchange mechanism. For example, it is known that rapid GB diffusion can transport a net current of atoms along GBs during both sintering and diffusional creep, and that the two species in a binary substitutional alloy diffuse at different rates in GBs. However, it has not been possible to establish firmly whether the defect mechanism involves the exchange of atoms with vacancy or interstitial point defects. It has been suspected that the vacancy exchange mechanism must apply but it has been difficult to prove this hypothesis because of a lack of detailed information at the atomistic level. The results are presented of an effort to establish the GB self-diffusion mechanism in a bcc iron ..sigma.. = 5 (36.9/sup 0/) (001) (310) tilt boundary using the combined methods of computer molecular statics and molecular dynamics simulation.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: AS02-78ER05002
• OSTI ID: 6470058
• Report Number(s): DOE/ER/05002-T3; COO-5002-23; ON: DE81025539
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
COMPUTER CALCULATIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELEMENTS
GRAIN BOUNDARIES
MATHEMATICAL MODELS
METALS
MICROSTRUCTURE
POINT DEFECTS
VACANCIES