Ultrasonic-induced excess vacancies in friction stir processing and exploration of acoustoplastic effect
| Autor: | Huijie Liu, Kazuki Sugita, Ke Liu, Hidetoshi Fujii, Yanying Hu, Hideki Araki |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Friction stir processing Condensed Matter::Other Mechanical Engineering Metals and Alloys 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Positron annihilation spectroscopy Condensed Matter::Materials Science Mechanics of Materials Peierls stress Vacancy defect 0103 physical sciences Hardening (metallurgy) Climb General Materials Science Composite material Dislocation 0210 nano-technology Softening |
| Zdroj: | Scripta Materialia. 185:117-121 |
| ISSN: | 1359-6462 |
| Popis: | The interactions of vacancy with dislocations and precipitates in the ultrasonic affected friction stir processing were investigated using positron annihilation spectroscopy, transmission electron microscopy and molecular dynamics simulation. Excess vacancies were induced by the ultrasonic via reducing the vacancy formation energy, resulting in a reduced Peierls stress and a concurrent enhancement of dislocation climb, contributing to the acoustic softening. In the cooling stage, appreciable helical dislocations were formed due to the quick condensations of vacancies on screw dislocations, leading to the residual hardening. |
| Databáze: | OpenAIRE |
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