Dislocation mobility and the mechanical response of b.c.c. single crystals: A mesoscopic approach

Journal Article · Fri May 22 04:00:00 EDT 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(98)00006-8· OSTI ID:619544

Tang, M ^[1]; Kubin, L P ^[2]; Canova, G R ^[3]

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1. Lawrence Livermore National Lab., CA (United States)
2. CNRS-ONERA, Chatillon (France)
3. GPM2-ENSPG, St. Martin d`Heres (France)

A mesoscopic simulation of dislocations and plasticity in b.c.c. crystals at low temperatures is developed and applied to the case of Ta. The thermally activated nucleation of double kinks is taken as controlling the mobility of screw dislocations. The resulting temperature and strain rate dependence of the yield stress are investigated and a detailed thermal activation analysis is performed on the output of the simulations. It is shown that within the simplifications made to the input parameters and slip geometry, one is able to simulate realistic dislocation structures and mechanical response. By checking the conformity between the input and output, it is shown that the essential dislocation property (activation energy for screw dislocation motion) can effectively be deduced from the mechanical tests. The mesoscopic simulation provides a potential tool to link atomistic studies at the microscopic scale to the macroscopic modeling of mechanical properties of b.c.c. metals at low temperatures.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 619544
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 9 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BCC LATTICES
COMPUTERIZED SIMULATION
DISLOCATIONS
MECHANICAL PROPERTIES
PLASTICITY
TANTALUM
TEMPERATURE DEPENDENCE
YIELD STRENGTH