scholarly journals EFFECT OF ARGON-ION IRRADIATION ON CAVITY FORMATION AND EVOLUTION IN 18Cr10NiTi AUSTENITIC STEEL

2020 ◽  
pp. 27-32
Author(s):  
G.D. Tolstolutskaya ◽  
S.A. Karpov ◽  
A.S. Kalchenko ◽  
I.E. Kopanets ◽  
A.V. Nikitin ◽  
...  

The swelling behavior of 18Cr10NiTi austenitic stainless steel irradiated with energetic Ar-ions in the dose range of 40…105 displacements per atom (dpa) with simultaneously implanted argon to the levels of 0.08…6.3 at.% at temperatures of 550…700 ºC was investigated. Transmission electron microscopy (TEM) has been used to study the microstructure evolution and to determine the dependence of swelling on the damage and Ar concentration. It is shown that the highest density and average size of the cavities was observed in the region of the calculated peak damage and Ar concentration. Argon was found to promote cavity swelling at lower temperature. At simultaneous creation of defects and argon implantation it was found a shift of swelling curve to higher temperatures compared to metallic-ion irradiation. The cavity swelling behavior of an austenitic 18Cr10NiTi steel irradiated with energetic argon ions are compared with those resulting from helium implantation.

1999 ◽  
Vol 585 ◽  
Author(s):  
S. Matsuo ◽  
M. Yamamoto ◽  
T. Sadoh ◽  
T. Tsurushima ◽  
D. W. Gao ◽  
...  

AbstractEffects of ion-irradiation on oxidation of silicon at low temperatures (130°C) in an argon and oxygen mixed plasma excited by electron cyclotron resonance (ECR) interaction are investigated. First, dependence of energy and flux of incident ions on the flow rate and the microwave power is evaluated. It is shown that the flow rate and the microwave power are key parameters for controlling the energy and the flux of incident ions, respectively. Second, growth kinetics of the oxide films are studied. The growth rate depends on the energy and the flux of argon ions irradiated to the substrate, and the growth thickness increases proportionally to the root square of the oxidation time. Thus, the growth rate is limited by diffusion of oxidants enhanced by irradiation with argon ions. The effect of substrate bias on oxidation characteristics is also discussed. The electrical properties of the oxide films are improved by increasing the bias. The improvement is due to the reduction of damage at the surface of the substrate induced by the irradiation.


2014 ◽  
Vol 1645 ◽  
Author(s):  
K. Hattar ◽  
O. El-Atwani ◽  
M. Efe ◽  
T.J. Novakowski ◽  
A. Suslova ◽  
...  

ABSTRACTMany theoretical predictions have suggested that the confined length scales and increased interface density of various nanostructured materials may result in desired thermal, mechanical, and radiation properties. An important aspect of this for next generation nuclear reactors is understanding the change in swelling resulting from helium evolution in tungsten alloys, as a function of grain size and grain boundary type. This study investigated this using a new ion irradiation transmission electron microscope (TEM) facility that has been developed at Sandia National Laboratories and is capable of ion implanting helium at energies up to 20 keV. It was demonstrated in this feasibility study that helium could be implanted into an ultrafine grained tungsten TEM sample produced by severe plastic deformation. The size and density of the helium bubbles formed during the experiment appear nearly constant; while the larger voids formed appear to be dependent on the local microstructure. Future work is underway to both optimize the facility, as well as better understand the evolution of ultrafine grained tungsten resulting from both helium implantation and displacement damage.


1988 ◽  
Vol 119 ◽  
Author(s):  
Guoan Cheng ◽  
Baixin Liu ◽  
Hengde Li

AbstractThe interfacial adhesion of Ti films on SiO2 substrate was studied by room temperature argon ion irradiation. Range of ion energy was chosen from 100 to 300 keV. Adhesive strength was measured by scratching test. For Ti/SiO2 pair irradiated by 100 keV argon ions, the adhesion was easier to enhance and much greater strength was obtained than that irradiated by 300 keV argon ions. The threshold dose also increased with the increasing of ion energy. The adhesive strength and the threshold dose increased when the metallizing temperatures were higher. Rutherford backscattering spectra(RBS) showed that a transition layer of about 10 nm thick was formed in Ti/SiO2 interface region after irradiation to a dose of 5X1016 Ar/cm2, indicating some chemical reaction has probably taken place. The experimental results are discussed in terms of thermodynamics of solids.


2011 ◽  
Vol 5 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Maja Popovic ◽  
Mirjana Novakovic ◽  
Zlatko Rakocevic ◽  
Natasa Bibic

In this work, the effects of 120 keV Ar+ ion implantation on the structural properties of TiN thin films were investigated. TiN layers were deposited by d.c. reactive sputtering on Si(100) wafers at room temperature or at 150?C. The thickness of TiN layers was ~240 nm. After deposition the samples were irradiated with 120 keV argon ions to the fluencies of 1?1015 and 1?1016 ions/cm2. Structural characterization was performed with Rutherford backscattering spectroscopy (RBS), cross-sectional transmission electron microscopy (XTEM), grazing angle X-ray diffraction (XRD) and atomic force microscopy (AFM). It was found that the argon ion irradiation induced the changes in the lattice constant, mean grain size, micro-strain and surface morphology of the TiN layers. The observed micro-structural changes are due to the formation of the high density damage region in the TiN thin film structure.


2021 ◽  
pp. 35-42
Author(s):  
V.N. Voyevodin ◽  
G.D. Tolstolutskaya ◽  
S.A. Karpov ◽  
A.N. Velikodnyi ◽  
M.A. Tikhonovsky ◽  
...  

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.


2020 ◽  
Vol 12 (2) ◽  
pp. 278-283
Author(s):  
Dipankar Chakdar ◽  
Abubakkar Siddik ◽  
Nikita Ghosh ◽  
Gautam Gope ◽  
Prabir Kumar Haldar

ZnO quantum dots of average size 10 nm are embedded in a matrix (polyvinyl alcohol (PVA)) following chemical route. They are irradiated by 100 MeV Ni7+ ion beam with fluences 1 × 1011, 3 × 1011, 1 × 1012 and 3 × 1012 ions/cm2. The optical absorption edge of irradiated quantum dots reveal negligible red shift with an increase in fluences with respect to that of unirradiated (virgin) ones. This fact clearly indicates no significant change in particle diameter under ion irradiation and is confirmed by high resolution transmission electron microscopy (TEM). AFM study also reveals the r.m.s surface roughness of the particles. It has also been observed that irradiated quantum dots produce similar type of photo luminescence and electroluminescence like virgin samples but the emission intensity increases remarkably after irradiation due to creation of large numbers oxygen vacancies by the ion beam.


1994 ◽  
Vol 353 ◽  
Author(s):  
T. J. White ◽  
R. C. Ewing ◽  
L. M. Wang ◽  
J. S. Forrester ◽  
C. Montross

AbstractA transmission electron microscope investigation was made of zirconolites and perovskites irradiated to amorphization with 1 MeV krypton ions using the HVEM-Tandem Facility at Argonne National Laboratory. Three specimens were examined - a prototype zirconolite CaZrTi2O7, a gadolinium doped zirconolite Ca0.75Gd0.50Zr0.75Ti2O7and a uranium doped zirconolite Ca0.75U0.50Zr0.75Ti2O7. The critical amorphization dose Dc was determined at several temperatures between 20K to 675K. Dc was inversely proportional with temperature. For example, pure zirconolite requiring 10x the dose for amorphization at 475K compared with gadolinium zirconolite. Using an Arrhenius plot, the activation energy Ea for annealing in these compounds was found to be 0.129 eV and 0.067 eV respectively. The greater ease of amorphization for the gadolinium sample is probably a reflection of this element’s large cross section for interaction with heavy ions. Uranium zirconolite was very susceptible to damage and amorphised under 4 keV argon ions during the preparation of microscope specimens. In each sample, zirconolite coexisted with minor perovskite, reduced rutile (Magneli phases) and zirconia. These phases were more resistant to ion irradiation than zirconolite. Even for high gadolinium loadings, perovskite (Ca0.8Gd0.2TiO3) was 3-4 times more stable to ion irradiation than the surrounding zirconolite crystals.


2010 ◽  
Vol 654-656 ◽  
pp. 2791-2794 ◽  
Author(s):  
Ryuta Kasada ◽  
Hiromasa Takahashi ◽  
Hirotatsu Kishimoto ◽  
Kentaro Yutani ◽  
Akihiko Kimura

The oxide dispersion strengthened (ODS) ferritic steel and non-ODS reduced-activation ferritic (RAF) steel were irradiated at 773 K by means of a dual-beam ion irradiation technique to a dose of 0.4 dpa with simultaneous helium implantation up to 1000 appm. Microstructural changes were investigated by transmission electron microscopy. The RAF steel showed a preferential formation of cavities at grain boundaries, precipitate interfaces and dislocations. In contrast, the ODS ferritic steel showed a homogeneous and fine distribution of cavities in the matrix. This paper discusses the superior resistance of the ODS ferritic steel against development of cavities in terms of the effects of nano-oxide particles dispersed in the matrix.


2021 ◽  
Vol 2144 (1) ◽  
pp. 012023
Author(s):  
P V Bykov ◽  
V L Vorob’ev ◽  
S G Bystrov ◽  
V V Tarasov ◽  
A Yu Drozdov ◽  
...  

Abstract The effect of argon ion irradiation with an energy of 40 keV in the dose range of 1016 - 1018 ion/cm2 on the formation of the surface layers composition, changes in the morphology and mechanical properties (microhardness, and wear resistance) of carbon steel AISI 1020 with a deposited ion-plasma coating Ni80Cr20 was studied. It is shown that irradiation with doses greater than 1017 ion/cm2 leads to the formation of a layer consisting of nickel, chromium and iron. The most optimal treatment mode for improving wear resistance is irradiation with a dose of 5.1017 ion/cm2.


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