Synergistic effects on dislocation loops in reduced-activation martensitic steel investigated by single and sequential hydrogen/helium ion irradiation

2016 ◽  
Vol 479 ◽  
pp. 302-306 ◽  
Author(s):  
Weiping Zhang ◽  
Fengfeng Luo ◽  
Yanxia Yu ◽  
Zhongcheng Zheng ◽  
Zhenyu Shen ◽  
...  
Keyword(s):  
Martensitic Steel ◽  
Ion Irradiation ◽  
Synergistic Effects ◽  
Dislocation Loops ◽  
Helium Ion

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 The Formation of Microcrystal in Helium Ion Irradiated Aluminum Alloy

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 516 ◽  
Author(s):  
Hao Wan ◽  
Shuai Zhao ◽  
Qi Jin ◽  
Tingyi Yang ◽  
Naichao Si
Keyword(s):  
Aluminum Alloy ◽  
Ion Irradiation ◽  
Dislocation Loops ◽  
Pinning Effect ◽  
Induced Stress ◽  
Transmission Electron ◽  
Helium Ion ◽  
Dislocation Defect ◽  
Defect Interactions ◽  
Main Factor

A microstructure variation in Al-1060 alloy after helium ion irradiation was revealed by a transmission electron microscope (TEM). The result shows that ion irradiation produced dislocations, dislocation loops, cavities and microcrystals in the irradiated layer. Dislocation-defect interactions were portrayed, especially the pinning effect of a dislocation loop and cavity on moving dislocation. Irradiation-induced stress was recognized as the main factor which impacted on the interaction of defect. Based on the dislocation inhibited with irradiation defects, the mechanism of microcrystal formation was proposed.

Synergistic Effects in Reduced-Activation Martensitic Steel Under Single and Sequential Helium/Hydrogen Ion Irradiation

2014 ◽  
Vol 66 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Jihong Chen ◽  
Liping Guo ◽  
Fengfeng Luo ◽  
Tiecheng Li ◽  
Yaoyao Ren ◽  
...  
Keyword(s):  
Martensitic Steel ◽  
Ion Irradiation ◽  
Synergistic Effects ◽  
Hydrogen Ion

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.

Magnetization dynamics of irradiation-fabricated perpendicularly magnetized dots inside a softer magnetic matrix

2003 ◽  
Vol 777 ◽  
Author(s):  
T. Devolder ◽  
M. Belmeguenai ◽  
C. Chappert ◽  
H. Bernas ◽  
Y. Suzuki
Keyword(s):  
Domain Wall ◽  
Magnetic Anisotropy ◽  
Magnetization Reversal ◽  
Ion Irradiation ◽  
Magnetic Nanostructures ◽  
Magnetic Storage ◽  
Exchange Field ◽  
Static Magnetization ◽  
Specific Domain ◽  
Helium Ion

AbstractGlobal Helium ion irradiation can tune the magnetic properties of thin films, notably their magneto-crystalline anisotropy. Helium ion irradiation through nanofabricated masks can been used to produce sub-micron planar magnetic nanostructures of various types. Among these, perpendicularly magnetized dots in a matrix of weaker magnetic anisotropy are of special interest because their quasi-static magnetization reversal is nucleation-free and proceeds by a very specific domain wall injection from the magnetically “soft” matrix, which acts as a domain wall reservoir for the “hard” dot. This guarantees a remarkably weak coercivity dispersion. This new type of irradiation-fabricated magnetic device can also be designed to achieve high magnetic switching speeds, typically below 100 ps at a moderate applied field cost. The speed is obtained through the use of a very high effective magnetic field, and high resulting precession frequencies. During magnetization reversal, the effective field incorporates a significant exchange field, storing energy in the form of a domain wall surrounding a high magnetic anisotropy nanostructure's region of interest. The exchange field accelerates the reversal and lowers the cost in reversal field. Promising applications to magnetic storage are anticipated.

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.

The influence of helium ion irradiation on amorphous hydrocarbon films

2013 ◽  
Vol 435 (1-3) ◽  
pp. 214-221 ◽  
Author(s):  
Hongyu Fan ◽  
Li Sun ◽  
Deming Yang ◽  
Jinhai Niu ◽  
Liping Guo ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Hydrocarbon Films ◽  
Helium Ion
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