scholarly journals Comparison between Subsequent Irradiation and Co-Irradiation into SIMP Steel

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1393
Author(s):  
Yong Wang ◽  
Tongmin Zhang ◽  
Qing Liao ◽  
Junyuan Yang ◽  
Weigang Gu ◽  
...  
Keyword(s):  
Martensitic Steel ◽  
Ion Irradiation ◽  
Material Microstructure ◽  
Critical System ◽  
Spallation Target ◽  
Lattice Disorder ◽  
Nano Indentation ◽  
Transmission Electron ◽  
Radiation Induced ◽  
New Perspective

A modern Chinese ferritic/martensitic steel SIMP, is a new perspective nuclear structural material for the spallation target in accelerator driven sub-critical system. In this work, aimed at exploring the radiation resistance properties of this material, we investigate the differences between simultaneous Fe and He ions irradiation and He implantation of SIMP steel pre-irradiated by Fe self-ions. The irradiations were performed at 300 °C. The radiation-induced hardening was evaluated by nano-indentation, while the lattice disorder was investigated by transmission electron microscopy. Clear differences were found in the material microstructure after the two kinds of the ion irradiation performed. Helium cavities were observed in the co-irradiated SIMP steel, but not the case of He implantation with Fe pre-irradiation. In the same time, the size and density of Frank loops were different in the two different irradiation conditions. The reason for the different observed lattice disorders is discussed.

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 EFFECT OF SEVERE PLASTIC DEFORMATION ON RADIATION HARDENING OF T91 FERRITIC-MARTENSITIC STEEL

2021 ◽  
pp. 35-42
Author(s):  
V.N. Voyevodin ◽  
G.D. Tolstolutskaya ◽  
S.A. Karpov ◽  
A.N. Velikodnyi ◽  
M.A. Tikhonovsky ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Martensitic Steel ◽  
Ion Irradiation ◽  
Dose Range ◽  
Fold Increase ◽  
Radiation Hardening ◽  
Dislocation Loops ◽  
Transmission Electron ◽  
Means Of Transmission

Effect of thermomechanical treatment on radiation hardening behavior in T91 ferritic-martensitic steel was evaluated. An applying of severe plastic deformation (SPD) by the “upsetting-extrusion” method and subsequent heat treatment led to a considerable grain refinement, crushing of martensite lamellas, reduction of MX carbides size and their more uniform distribution. Nanoindentation measurements of SPD-modified steel revealed a 1.4-fold increase in the hardness relative to the initial steel. Irradiation response of modified steel was examined after 1.4 MeV Ar+ ion irradiations in the dose range of 10…45 displacements per atom (dpa) at room temperature and 460 °C. Microstructure characterization was performed by means of transmission electron microscopy (TEM). It was found that dislocation loops and nano-sized argon bubbles dominated the damage microstructure after ion irradiation. The effects of SPD-induced transformations as well as nano-bubbles formation are discussed regarding to the hardening phenomenon observed in irradiated steel.

scholarly journals Electron Beam Effects during In-Situ Annealing of Self-Ion Irradiated Nanocrystalline Nickel

2015 ◽  
Vol 1809 ◽  
pp. 13-18 ◽  
Author(s):  
Brittany Muntifering ◽  
Rémi Dingreville ◽  
Khalid Hattar ◽  
Jianmin Qu
Keyword(s):  
Electron Beam ◽  
Nuclear Reactor ◽  
Ion Irradiation ◽  
Nanocrystalline Nickel ◽  
Transmission Electron ◽  
Radiation Induced ◽  
Reactor Materials ◽  
Diffraction Patterns ◽  
Underlying Mechanisms

ABSTRACTTransmission electron microscopy (TEM) is a valuable methodology for investigating radiation-induced microstructural changes and elucidating the underlying mechanisms involved in the aging and degradation of nuclear reactor materials. However, the use of electrons for imaging may result in several inadvertent effects that can potentially change the microstructure and mechanisms active in the material being investigated. In this study, in situ TEM characterization is performed on nanocrystalline nickel samples under self-ion irradiation and post irradiation annealing. During annealing, voids are formed around 200 °C only in the area illuminated by the electron beam. Based on diffraction patterns analyses, it is hypothesized that the electron beam enhanced the growth of a NiO layer resulting in a decrease of vacancy mobility during annealing. The electron beam used to investigate self-ion irradiation ultimately significantly affected the type of defects formed and the final defect microstructure.

HRTEM Study of the Role of Nanoparticles in ODS Ferritic Steel under Dual-Ion Irradiation

2011 ◽  
Vol 1296 ◽  
Author(s):  
Luke Hsiung ◽  
Scott Tumey ◽  
Michael Fluss ◽  
Yves Serruys ◽  
Francois Willaime
Keyword(s):  
Mechanical Alloying ◽  
Ferritic Steel ◽  
Ion Irradiation ◽  
Complex Oxide ◽  
Helium Bubbles ◽  
Ods Steel ◽  
Transmission Electron ◽  
Radiation Induced ◽  
State Amorphization

ABSTRACTStructures of nanoparticles and their role in dual-ion irradiated Fe-16Cr-4.5Al-0.3Ti-2W-0.37Y2O3 (K3) ODS ferritic steel produced by mechanical alloying (MA) were studied using high-resolution transmission electron microscopy (HRTEM) techniques. The observation of Y4Al2O9 complex-oxide nanoparticles in the ODS steel imply that decomposition of Y2O3 in association with internal oxidation of Al occurred during mechanical alloying. HRTEM observations of crystalline and partially crystalline nanoparticles larger than ~2 nm and amorphous cluster-domains smaller than ~2 nm provide an insight into the formation mechanism of nanoparticles/clusters in MA/ODS steels, which we believe involves solid-state amorphization and re-crystallization. The role of nanoparticles/clusters in suppressing radiation-induced swelling is revealed through TEM examinations of cavity distributions in (Fe + He) dual-ion irradiated K3-ODS steel. HRTEM observations of helium-filled cavities (helium bubbles) preferably trapped at nanoparticle/clusters in dual-ion irradiated K3-ODS are presented.

Radiation Induced Structural Changes in Normal Spinels

2007 ◽  
Vol 1043 ◽  
Author(s):  
David Simeone ◽  
Gianguido Baldinozzi ◽  
Dominique Gosset ◽  
Leo Mazerolles ◽  
Lionel Thome
Keyword(s):  
Radiation Effects ◽  
Structural Changes ◽  
Ion Irradiation ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
Unified Framework ◽  
X Ray ◽  
Transmission Electron ◽  
Radiation Induced ◽  
Diffraction Patterns

AbstractIon irradiation induced phase transformations in three normal spinel compounds MgAl2O4, MgCr2O4 and ZnAl2O4 have been investigated by X-ray diffraction, Raman spectroscopy and Transmission Electron Microscopy. This work presents a unified framework to describe the radiation effects in normal spinels. Irradiation modifies the atomic and mesoscopic structures of theses spinels in different ways. At the atomic scale, it produces the inversion of the cations in the spinel structure which can always be described within its usual Fd-3m space group. At the mesoscopic scale, it produces microdomains, responsible for the important changes in the X-ray diffraction patterns.

scholarly journals Ion irradiation induced phase transformation in gold nanocrystalline films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pranav K. Suri ◽  
James E. Nathaniel ◽  
Nan Li ◽  
Jon K. Baldwin ◽  
Yongqiang Wang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Ion Irradiation ◽  
Face Centered Cubic ◽  
Ambient Conditions ◽  
Free Standing ◽  
Hexagonal Close Packed ◽  
Transmission Electron ◽  
Precession Electron Diffraction ◽  
Radiation Induced ◽  
Face Centered

Abstract Gold is a noble metal typically stable as a solid in a face-centered cubic (FCC) structure under ambient conditions; however, under particular circumstances aberrant allotropes have been synthesized. In this work, we document the phase transformation of 25 nm thick nanocrystalline (NC) free-standing gold thin-film via in situ ion irradiation studied using atomic-resolution transmission electron microscopy (TEM). Utilizing precession electron diffraction (PED) techniques, crystallographic orientation and the radiation-induced relative strains were measured and furthermore used to determine that a combination of surface and radiation-induced strains lead to an FCC to hexagonal close packed (HCP) crystallographic phase transformation upon a 10 dpa radiation dose of Au4+ ions. Contrary to previous studies, HCP phase in nanostructures of gold was stabilized and did not transform back to FCC due to a combination of size effects and defects imparted by damage cascades.

Annealing Of Radiation Damage in Tungsten

1970 ◽  
Vol 28 ◽  
pp. 412-413
Author(s):  
Robert C. Rau ◽  
John Moteff
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radiation Damage ◽  
Thermal Annealing ◽  
Neutron Fluence ◽  
Dislocation Loops ◽  
Defect Clusters ◽  
Polycrystalline Tungsten ◽  
Transmission Electron ◽  
Radiation Induced

Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in polycrystalline tungsten. Specimens were taken from cylindrical tensile bars which had been irradiated to a fast (E > 1 MeV) neutron fluence of 4.2 × 1019 n/cm2 at 70°C, annealed for one hour at various temperatures in argon, and tensile tested at 240°C in helium. Foils from both the unstressed button heads and the reduced areas near the fracture were examined.Figure 1 shows typical microstructures in button head foils. In the unannealed condition, Fig. 1(a), a dispersion of fine dot clusters was present. Annealing at 435°C, Fig. 1(b), produced an apparent slight decrease in cluster concentration, but annealing at 740°C, Fig. 1(C), resulted in a noticeable densification of the clusters. Finally, annealing at 900°C and 1040°C, Figs. 1(d) and (e), caused a definite decrease in cluster concentration and led to the formation of resolvable dislocation loops.

Xenon ion irradiation of superconducting YBa2Cu3O7 thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 92-93
Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban
Keyword(s):  
Defect Formation ◽  
Ion Irradiation ◽  
High Resolution Electron Microscopy ◽  
Structural Disorder ◽  
Flux Lines ◽  
Pinning Effect ◽  
Magnetic Flux Lines ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Induced Defects

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.

Transmission Electron Microscopy characterization of epitaxial III-V semiconductor thin films grown on Si(100) by ion-assisted deposition

1990 ◽  
Vol 48 (4) ◽  
pp. 686-687
Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Irradiation ◽  
High Energy ◽  
Nucleation Mechanism ◽  
Layer By Layer ◽  
Extended Defect ◽  
Island Formation ◽  
Si Substrates ◽  
Transmission Electron

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.

Sign in / Sign up

Export Citation Format

Share Document