scholarly journals The Effect of Yttrium Addition on the Microstructure and Irradiation Hardening in V-4Cr-4Ti Alloy under Self-Ion Irradiation

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1024
Author(s):  
Hongtai Luo ◽  
Fengfeng Luo ◽  
Yiheng Chen ◽  
Jiawei Wang ◽  
Qiuxiang Liu ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Indentation Test ◽  
Vanadium Alloy ◽  
Dislocation Loops ◽  
Number Density ◽  
Irradiation Hardening ◽  
Nano Indentation ◽  
Yttrium Addition ◽  
Test Technology ◽  
Average Size

Microstructure and irradiation hardening of V-4Cr-4Ti alloys with different yttrium (Y) contents were studied by self-ion irradiation at 550 °C via TEM and nano-indentation test technology. The peak damage of the V-4Cr-4Ti-xY alloy (x = 0, 0.1, 0.5, and 1, wt.%) irradiated by 2.5 MeV self-ion (V2+) is 8 dpa. Dense dislocation loops were observed in all vanadium alloy samples after irradiation. With the increase of Y content, both average size and number density of dislocation loops using g = <110> near the pole [001] decreased, while the irradiation hardness increment first decreased and then increased. In order to better reduce the irradiation hardening, it is considered that the addition of 0.1 wt.% Y in V-4Cr-4Ti alloy is reasonable.

Elastic–plastic-damage model of nano-indentation of the ion-irradiated 6061 aluminium alloy

2020 ◽  
Vol 29 (8) ◽  
pp. 1271-1305
Author(s):  
A Ustrzycka ◽  
B Skoczeń ◽  
M Nowak ◽  
Ł Kurpaska ◽  
E Wyszkowska ◽  
...  
Keyword(s):  
Damage Evolution ◽  
Damage Mechanics ◽  
Ion Irradiation ◽  
Damage Model ◽  
Indentation Test ◽  
Gtn Model ◽  
Damage Level ◽  
Nano Indentation ◽  
Wide Range ◽  
Radiation Induced

The paper presents experimental and numerical characterization of damage evolution for ion-irradiated materials subjected to plastic deformation during nano-indentation. Ion irradiation technique belongs to the methods where creation of radiation-induced defects is controlled with a high accuracy (including both, concentration and depth distribution control), and allows to obtain materials having a wide range of damage level, usually expressed in terms of displacements per atom (dpa) scale. Ion affected layers are usually thin, typically less than 1 micrometer thick. Such a low thickness requires to use nano-indentation technique to measure the mechanical properties of the irradiated layers. The He or Ar ion penetration depth reaches approximately 150 nm, which is sufficient to perform several loading-partial-unloading cycles at increasing forces. Damage evolution is reflected by the force-displacement diagram, that is backed by the stress–strain relation including damage. In this work the following approach is applied: dpa is obtained from physics (irradiation mechanisms), afterwards, the radiation-induced damage is defined in the framework of continuum damage mechanics to solve the problem of further evolution of damage fields under mechanical loads. The nature of radiation-induced damage is close to porosity because of formation of clusters of vacancies. The new mathematical relation between radiation damage (dpa) and porosity parameter is proposed. Deformation process experienced by the ion irradiated materials during the nano-indentation test is then numerically simulated by using extended Gurson–Tvergaard–Needleman (GTN) model, that accounts for the damage effects. The corresponding numerical results are validated by means of the experimental measurements. It turns out, that the GTN model quite successfully reflects closure of voids, and increase of material density during the nano-indentation.

Evaluation of Irradiation Hardening of Fe-Ion Irradiated F82H by Nano-Indentation Techniques

2010 ◽  
Vol 654-656 ◽  
pp. 2915-2918 ◽  
Author(s):  
Yoshiyuki Takayama ◽  
Ryuta Kasada ◽  
Kiyohiro Yabuuchi ◽  
Akihiko Kimura ◽  
Dai Hamaguchi ◽  
...  
Keyword(s):  
Experimental Test ◽  
Fusion Reactor ◽  
Martensitic Steel ◽  
Ion Irradiation ◽  
Test Method ◽  
Irradiation Hardening ◽  
Nano Indentation ◽  
Ni Addition ◽  
Fusion Reactor Blanket ◽  
Hardness Depth

The effects of small amount (1 or 2 wt.%) of Ni additionson the irradiation hardening of the reduced-activation ferritic/martensitic steel, F82H, used as fusion reactor blanket structural materials were investigated by means of Fe-ion irradiation experimental test method and nano-indentation technique. The ion-irradiation hardening of Ni-added F82H is larger than that of the steel without Ni addition. The methodology to derive the irradiation hardening of ion-irradiated F82H steel was proposed from the results of hardness depth profile.

scholarly journals Evaluation of helium effect on ion-irradiation hardening in pure tungsten by nano-indentation method

2016 ◽  
Vol 9 ◽  
pp. 539-546 ◽  
Author(s):  
Zhexian Zhang ◽  
Eva Hasenhuetl ◽  
Kiyohiro Yabuuchi ◽  
Akihiko Kimura
Keyword(s):  
Ion Irradiation ◽  
Pure Tungsten ◽  
Indentation Method ◽  
Irradiation Hardening ◽  
Nano Indentation

Effets of surfaces on precipitate morphology in irradiated thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 654-655
Author(s):  
D.I. Potter ◽  
A. Taylor
Keyword(s):  
Ion Irradiation ◽  
Dark Field Image ◽  
Thin Foil ◽  
Dark Field ◽  
Al Alloy ◽  
Bright Field Image ◽  
Dislocation Loops ◽  
Precipitate Morphology ◽  
Thin Foils

Thermal aging of Ni-12.8 at. % A1 and Ni-12.7 at. % Si produces spatially homogeneous dispersions of cuboidal γ'-Ni3Al or Ni3Si precipitate particles arrayed in the Ni solid solution. We have used 3.5-MeV 58Ni+ ion irradiation to examine the effect of irradiation during precipitation on precipitate morphology and distribution. The nearness of free surfaces produced unusual morphologies in foils thinned prior to irradiation. These thin-foil effects will be important during in-situ investigations of precipitation in the HVEM. The thin foil results can be interpreted in terms of observations from bulk irradiations which are described first.Figure 1a is a dark field image of the γ' precipitate 5000 Å beneath the surface(∿1200 Å short of peak damage) of the Ni-Al alloy irradiated in bulk form. The inhomogeneous spatial distribution of γ' results from the presence of voids and dislocation loops which can be seen in the bright field image of the same area, Fig. 1b.

scholarly journals Irradiation Hardening Behavior of He-Irradiated V–Cr–Ti Alloys with Low Ti Addition

2020 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Ken-ichi Fukumoto ◽  
Yoshiki Kitamura ◽  
Shuichiro Miura ◽  
Kouji Fujita ◽  
Ryoya Ishigami ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Optimum Composition ◽  
Solid Solution Hardening ◽  
Irradiation Hardening ◽  
Hardening Behavior ◽  
Ti Alloys ◽  
Void Swelling ◽  
Before And After ◽  
Cr Addition ◽  
Ti Addition

A set of V–(4–8)Cr–(0–4)Ti alloys was fabricated to survey an optimum composition to reduce the radioactivity of V–Cr–Ti alloys. These alloys were subjected to nano-indenter tests before and after 2-MeV He-ion irradiation at 500 °C and 700 °C with 0.5 dpa at peak damage to investigate the effect of Cr and Ti addition and gas impurities for irradiation hardening behavior in V–Cr–Ti alloys. Cr and Ti addition to V–Cr–Ti alloys for solid–solution hardening remains small in the unirradiated V–(4–8)Cr–(0–4)Ti alloys. Irradiation hardening occurred for all V–Cr–Ti alloys. The V–4Cr–1Ti alloy shows the highest irradiation hardening among all V–Cr–Ti alloys and the gas impurity was enhanced to increase the irradiation hardening. These results may arise from the formation of Ti(CON) precipitate that was produced by He-ion irradiation. Irradiation hardening of V–Cr–1Ti did not depend significantly on Cr addition. Consequently, for irradiation hardening and void-swelling suppression, the optimum composition of V–Cr–Ti alloys for structural materials of fusion reactor engineering is proposed to be a highly purified V–(6–8)Cr–2Ti alloy.

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Nucleation and amorphization of radiation-produced phases in a modified austenitic stainless steel during Ni-ion irradiation

1988 ◽  
Vol 3 (5) ◽  
pp. 840-844 ◽  
Author(s):  
E. H. Lee ◽  
E. A. Kenik
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ion Irradiation ◽  
Amorphous State ◽  
Dislocation Loops ◽  
Nickel Ion ◽  
Carbide Phases ◽  
Direct Formation ◽  
Radiation Induced ◽  
Lower Temperature

The nucleation and amorphization of radiation-induced (G) and radiation-enhanced (η) phases in a silicon- and titanium-modified austenitic stainless steel have been studied under nickel-ion irradiation. These silicon- and nickel-enriched phases form under high-temperature (950 K) irradiation as the result of radiation-induced segregation to radiation-produced interstitial dislocation loops. Availability of carbon promotes the formation of η phase relative to G phase. Under lower temperature (450 K) irradiation, G and η phases are amorphized without significant change in composition of metallic elements. Two carbide phases (MC, M23C6) remain crystalline for the same irradiation conditions. The amorphization of the silicides may result from (1) radiation damage increasing their free energy above that of the amorphous state or (2) direct formation of the amorphous phase in the damage cascade.

scholarly journals Ion Irradiation-Induced Microstructural Evolution of Ni–Mo–Cr Low Alloy Steels

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2268
Author(s):  
Hongying Sun ◽  
Penghui Lei ◽  
Guang Ran ◽  
Hui Wang ◽  
Jiyun Zheng ◽  
...  
Keyword(s):  
Irradiation Dose ◽  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
High Strength ◽  
Positron Annihilation Spectroscopy ◽  
Small Scale ◽  
Low Alloy Steels ◽  
Dislocation Loops ◽  
S Parameter

As leading candidates of sheet steels for advanced nuclear reactors, three types of Ni–Mo–Cr high-strength low alloy (HSLA) steels named as CNST1, CNST2 and CNSS3 were irradiated by 400 keV Fe+ with peak fluence to 1.4 × 1014, 3.5 × 1014 and 7.0 × 1014 ions/cm2, respectively. The distribution and morphology of the defects induced by the sample preparation method and Fe+ irradiation dose were investigated by transmission electron microscopy (TEM) and positron-annihilation spectroscopy (PAS). TEM samples were prepared with two methods, i.e., a focused ion beam (FIB) technique and the electroplating and twin-jet electropolishing (ETE) method. Point defects and dislocation loops were observed in CNST1, CNST2 and CNSS3 samples prepared via FIB. On the other hand, samples prepared via the ETE method revealed that a smaller number of defects was observed in CNST1, CNST2 and almost no defects were observed in CNST3. It is indicated that artifact defects could be introduced by FIB preparation. The PAS S-W plots showed that the existence of two types of defects after ion implantation included small-scale defects such as vacancies, vacancy clusters, dislocation loops and large-sized defects. The S parameter of irradiated steels showed a clear saturation in PAS response with increasing Fe+ dose. At the same irradiation dose, higher values of the S-parameter were achieved in CNST1 and CNST2 samples when compared to that in CNSS3 samples. The mechanism and evolution behavior of irradiation-induced defects were analyzed and discussed.

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