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Characterization of dislocation loops in hydrogen-ion irradiated vanadium
- Source :
- Acta Physica Sinica. 65:066102
- Publication Year :
- 2016
- Publisher :
- Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, 2016.
-
Abstract
- Vanadium alloys are considered as the candidate materials for structure application in fusion reactors because of their low radiation-induced activation, high resistance to radiation damage, high thermal conduction, and low thermal expansion coefficient. Before these materials, which will be exposed to high-flux hydrogen and helium isotopes, may be safely used in fusion device much more data based on irradiation damage are required. The study of dislocation loops in vanadium is designed to indicate the mechanism of void growing under irradiation. The mechanism is that different types of dislocation loops have different bias which represent their abilities to absorb point defects. It is possible to explain the irradiation swelling performance in the material with the bias of loops. The thin disks samples used in this experiment are made of pure vanadium and vanadium alloy (V-4Cr-4Ti) by twin-jet electro-polishing. Electrolyte of H2SO4-CH3OH (1 : 6 by volume) at -20 ℃ is used in a current of 80~120 mA. To get a clear view of dislocation loops, the SRIM code is used to simulate the implantation of hydrogen ions into vanadium. The ion irradiation is carried out to a dose of 51016H+/cm2, at an energy of 30 keV. Microstructure observations are performed on a Tecnai G2 F20 (transmission electron microscope, TEM) at an accelerating voltage of 200 kV. The Burger's vectors and nature of the dislocation loops formed in pure vanadium by hydrogen implantation are confirmed by TEM. This experiment has focused on as many as 76 dislocation loops, lots of images are taken under different diffraction conditions from the same areas of interest. Results show that most of the dislocation loops have a Burger's vectors of 1/2111 (90%), and a few of 110. No loops with b= 100 loops can be found in this study. The nature of dislocation loops is determined by the inside-outside method. The number of the dislocation loops that can make sure of their nature is 29, and all of them are conformed to be interstitial type, their habit planes are from {110} to {112}. No vacancy type loops are found. The density and average size of dislocation loops in vanadium and vanadium alloy are also analysed. Compared with the pure vanadium, the loops in vanadium alloy of V-4Cr-Ti are formed in a smaller size and higher number density. As a future work the difference of the loops nature between pure vanadium and vanadium-based alloys should be investigated to illustrate their behaviour of irradiation swelling.
- Subjects :
- 010302 applied physics
Hydrogen ion
Materials science
Hydrogen
General Physics and Astronomy
chemistry.chemical_element
Vanadium
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Characterization (materials science)
chemistry
Transmission electron microscopy
0103 physical sciences
Physical chemistry
Irradiation
Dislocation
0210 nano-technology
Subjects
Details
- ISSN :
- 10003290
- Volume :
- 65
- Database :
- OpenAIRE
- Journal :
- Acta Physica Sinica
- Accession number :
- edsair.doi...........514736bda68e5d695b5f3b8625e4213b