In situ creep under helium implantation of titanium–aluminium alloy

Chen, J.; Jung, P.; Nazmy, M.; Hoffelner, Wolfgang

doi:10.1016/j.jnucmat.2006.02.039

Cited by 16 publications

(13 citation statements)

References 18 publications

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“…One possible explanation for enhanced irradiation creep at temperatures of about 600°C could be that at this temperature thermal creep already becomes the important mechanism for this material. This behavior which was observed also for PM2000 and TiAl [61,62] would explain also why no irradiation creep effects were detected for in-pile creep of advanced ODS materials at temperatures of 700°C and higher [63]. These results seem to demonstrate that the presence of dispersoids does not have a significant influence on the irradiation creep behavior.…”

Section: Creep Under Irradiationsupporting

confidence: 63%

Damage assessment in structural metallic materials for advanced nuclear plants

Hoffelner

2010

J Mater Sci

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Future advanced nuclear plants are considered to operate as cogeneration plants for electricity and heat. Metals and alloys will be the main portion of structural materials employed (including fuel claddings). Due to the operating conditions these materials are exposed to damaging conditions like creep, fatigue, irradiation and its combinations. The paper uses the most important alloys: ferritic-martensitic steels, superalloys, oxide dispersion strengthened steels and to some extent titanium aluminides to discuss its responses to these exposure conditions. Extrapolation of stress rupture data, creep strain, swelling, irradiation creep and creep-fatigue interactions are considered. Although the stress rupture-and the creep behavior seem to meet expectations, the long design lives of 60 years are really challenging for extrapolations and particularly questions like negligible creep or occurrence of diffusion creep need special attention. Ferritic matrices (including oxide dispersion strengthened (ODS), steels) have better irradiation swelling behavior than austenites. Presence and size of dispersoids having a strong influence on high-temperature strength bring only insignificant improvements in irradiation creep. A strain-range-separation based approach for creep-fatigue interactions is presented which allows a real prediction of creep-fatigue lives. An assessment of capabilities and limitations of advanced materials modeling tools with respect to damage development is given.

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Section: Creep Under Irradiationsupporting

confidence: 63%

Damage assessment in structural metallic materials for advanced nuclear plants

Hoffelner

2010

J Mater Sci

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“…Titanium alloys have found widening trends of application in the aerospace industry, as biomaterials for orthopedic and oral implantations, in chemical and ship building industries, in offshore structures for extraction of hydrocarbons and piping systems, in nuclear power plants and reactors, as shape memory alloys, in automotive components such as turbochargers and valves, and as coating materials for cutting tools (Ref [6][7][8][9][10][11][12][13][14][15][16][17][18]. This increasing demand for titanium is attributable to its favorable properties including high specific strength, low density, corrosion resistance, weldability, and relatively elevated-temperature resistance ( Ref 9,[19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Experiments with a Low-Cost Hot Isothermal Pressing Machine Developed for Superplastic Forming

Nategh

Jafari

2008

J. of Materi Eng and Perform

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Hot isothermal/isostatic pressing machines are technically good candidates for superplastic forming (SPF) of otherwise hard-to-shape materials such as superalloys. These machines are, however, very expensive so that small or medium-size enterprises can not afford them. This has impeded widespread use of SPF processing. In an attempt to alleviate the problem, the authors have developed a laboratory model of an affordable hot isothermal pressing machine with differential gas pressure as the forming medium. Careful selection of process parameters such as temperature, gas pressure, strain rate, and process time as well as monitoring of thickness changes in a workpiece has a pivotal role in successful operation of such machine. It has been illustrated in this article that SPF can be successfully performed with this machine on the basis of process parameters estimated with existing analytical relations. The performance of this machine has been verified by several experiments on SPF of titanium-based sheets, as reported in this article.

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“…The main peak was made trending to the (101) plane by both higher deposition temperature and more helium trapping. magnetron sputtering, relative helium content, titanium filmThe study of "Helium Problems" in metals is referred to in many realms of nuclear energy technology [1][2][3][4][5] . It is very important to the research of the characteristics of keeping tritium materials for using nuclear energy peaceably and militarily.…”

mentioning

confidence: 99%

“…The pure metal of titanium is considered as the best material of keeping tritium, which is used as tritium target usually. 3 He produced from tritium disintegration is migratory in metals and has a strong tendency to get together at room temperature. Metal atoms are piled out of the original places and helium bubbles come into being when helium atoms get together to a critical range [6][7][8][9] .…”

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confidence: 99%

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Effects of helium on titanium films and the helium diffusion

et al. 2008

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Using direct current-magnetron sputtering, Helium-trapped Ti films with a He/Ar mixture was studied. The relative helium content, helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhanced Proton Backscattering Spectrometry (EPBS) and X-ray diffraction (XRD). It was found that helium diffusion enhanced as more helium trapping into Ti films, and the He holding ratios were 95.9%, 94.9%, 93.9%, 82.8% when the Ti films with the He/Ti of concentrations of 9.7 at.%, 19.5 at.%, 19.7 at.%, 48.3 at.% were measured again 4 months later, respectively. The diffraction peaks became weak and wider, the peak of (002) plane was shifted to smaller diffraction angles and the relevant interplanar spacing d (hkl) increased gradually as more helium trapping into Ti films. The main peak was made trending to the (101) plane by both higher deposition temperature and more helium trapping. magnetron sputtering, relative helium content, titanium filmThe study of "Helium Problems" in metals is referred to in many realms of nuclear energy technology [1][2][3][4][5] . It is very important to the research of the characteristics of keeping tritium materials for using nuclear energy peaceably and militarily. The pure metal of titanium is considered as the best material of keeping tritium, which is used as tritium target usually. 3 He produced from tritium disintegration is migratory in metals and has a strong tendency to get together at room temperature. Metal atoms are piled out of the original places and helium bubbles come into being when helium atoms get together to a critical range [6][7][8][9] . The helium bubbles grow up gradually and become dense with the increasing of 3 He atoms in metals. The large number of helium bubbles in metal will debase the capability of the material. This is the first problem to produce helium within these materials expediently and speedily. In order to study helium diffusion, a large number of helium is uniformly introduced into metals with no displacement damage by direct current (DC)-magnetron sputtering (there is low energy helium implantation in the technics).Helium charging in the Ti films was usually deposited starting at room temperature (not being heated up) or keeping at high constant temperature in previous literatures. No reports have been found that the deposition is completed by combining the two steps. We now conduct these experiments because it is advantageous to the study of helium diffusion and the best helium-charged capability of Ti films at high temperature (the relative helium content of which deposited just at high constant temperature is very rare but quite common at room temperature [10,11] ).A Ti disk (99.99% in purity, 65 mm in diameter and 7 mm in thickness) was used as the target. The distance between the target and the substrate (Mo, φ18×1 mm) was adjusted to 55 mm. All the substrates were fastened on a holder which could be heated by a resistive heater, and a −60 V bias was applied to the holder. The sub-

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In situ creep under helium implantation of titanium–aluminium alloy

Cited by 16 publications

References 18 publications

Damage assessment in structural metallic materials for advanced nuclear plants

Damage assessment in structural metallic materials for advanced nuclear plants

Experiments with a Low-Cost Hot Isothermal Pressing Machine Developed for Superplastic Forming

Effects of helium on titanium films and the helium diffusion

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