Atomistic simulation for configuration evolution and energetic calculation of crack in body-centered-cubic iron
Autor: | Li-Xia Cao, Chong-Yu Wang |
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Rok vydání: | 2006 |
Předmět: |
Materials science
Mechanical Engineering Nucleation Fracture mechanics Condensed Matter Physics Physics::Geophysics Condensed Matter::Materials Science Crack closure Crystallography Brittleness Fracture toughness Mechanics of Materials Partial dislocations General Materials Science Composite material Deformation (engineering) Crystal twinning |
Zdroj: | Journal of Materials Research. 21:2542-2549 |
ISSN: | 2044-5326 0884-2914 |
DOI: | 10.1557/jmr.2006.0307 |
Popis: | The molecular dynamics method has been used to simulate mode I cracking in body-centered-cubic iron. Close attention has been paid to the process of the atomic configuration evolution of the cracks. The simulation shows that at low temperatures, partial dislocations are emitted before the initiation of crack propagation, subsequently forming the stacking faults or multilayer twins on {112} planes, and then brittle cleavage and extended dislocation nucleation are observed at the crack tip accompanied by twin extension. These results are in agreement with the experimental observation that twinning and fracture processes cooperate at low temperatures. Furthermore, an energetics analysis has been made on the deformation behavior observed at the crack tip. The effect of temperature on the fracture process is discussed. At the higher temperature, plastic deformation becomes easier, and crack blunting occurs. With increasing temperature, the fracture resistance increases, and the effect of the lattice trapping can be weakened by thermal activation. |
Databáze: | OpenAIRE |
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