Correlation of radiation-induced changes in mechanical properties and microstructural development of Alloy 718 irradiated with mixed spectra of high-energy protons and spallation neutrons

The possibility of modifying polyethylene and many other polymers with high energy radiation has led to many useful applications. Due to their new combination of properties and the shortage of experimental data, the radiolysis of a new class of materials, cyclo-olefin copolymers (COC), polymerised from norbornene and ethylene using metallocene catalysts, is of great interest to the study of radiation chemistry and the physics of polymeric systems. Ethylenenorbornene copolymer, pristine and containing an antioxidant were subjected to gamma irradiation in the presence of air and in water. The irradiated copolymer was studied using IR and UV-vis spectrophotometric analysis. The radiation-induced changes in the molecular structure were correlated to changes in the glass transition temperature measured by the DSC method.

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The Effect of Bulk Composition on Swelling and Radiation-Induced Segregation in Austenitic Alloys

MRS Proceedings ◽

10.1557/proc-650-r3.12 ◽

2000 ◽

Vol 650 ◽

Cited By ~ 1

Author(s):

T. R. Allen ◽

J. I. Cole ◽

N. L. Dietz ◽

Y. Wang ◽

G. S. Was ◽

...

Keyword(s):

Stainless Steel ◽

Grain Boundary ◽

Bulk Composition ◽

High Energy ◽

Lattice Parameter ◽

304 Stainless Steel ◽

Microstructural Development ◽

Nickel Concentration ◽

Void Swelling ◽

Radiation Induced

ABSTRACTChanges in bulk composition are known to affect both radiation-induced segregation and microstructural development, including void swelling in austenitic stainless steel. In this work, three alloys (designations corresponding to wt%) have been studied: Fe-18Cr-8Ni alloy (bulk composition corresponding to 304 stainless steel), Fe-18Cr-40Ni (bulk composition corresponding to 330 stainless steel), and Fe-16Cr-13Ni (bulk composition corresponding to 316 stainless steel). Following irradiation with high-energy protons, the change in hardness and microstructure (void size distribution and grain boundary composition) due to irradiation was investigated. Increasing the bulk nickel concentration decreases void swelling, increases matrix hardening, and increases grain boundary chromium depletion and nickel enrichment. The analysis shows that decreases in lattice parameter and shear modulus due to radiation- induced segregation (RIS) correlate with decreased void swelling and a decreased susceptibility to irradiation assisted stress corrosion cracking (IASCC). Traditional thinking on IASCC assumed RIS was a contributing factor to cracking. It may, however, be that properly controlled RIS can be used to mitigating cracking.

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Methods of predicting radiation-induced changes in the mechanical properties of high polymers

Journal of Polymer Science ◽

10.1002/pol.1962.1205716549 ◽

1962 ◽

Vol 57 (165) ◽

pp. 629-639

Author(s):

E. G. Fritz

Keyword(s):

Mechanical Properties ◽

Radiation Induced ◽

Induced Changes ◽

High Polymers

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High-Energy Radiation-Induced Changes in the Crystal Morphology of Cellulose

Macromolecules ◽

10.1021/ma030528z ◽

2004 ◽

Vol 37 (7) ◽

pp. 2668-2670 ◽

Cited By ~ 4

Author(s):

Frederick G. Morin ◽

Byron D. Jordan ◽

Robert H. Marchessault

Keyword(s):

Crystal Morphology ◽

High Energy ◽

High Energy Radiation ◽

Energy Radiation ◽

Radiation Induced ◽

Induced Changes

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Radiation-induced changes in the structure of polypropylene

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1959.0197 ◽

1959 ◽

Vol 253 (1274) ◽

pp. 322-330 ◽

Cited By ~ 30

Keyword(s):

Main Chain ◽

High Energy ◽

Theoretical Expression ◽

Cross Linking ◽

Gel Point ◽

High Energy Radiation ◽

Infra Red ◽

Radiation Induced ◽

Induced Changes ◽

Good Agreement

Polypropylene undergoes both cross-linking and random main-chain fracture when exposed to high-energy radiation, the ratio of cross-linking to chain fracture varying with the dose received up to the gel point. An examination of the infra-red absorption spectrum of the irradiated polymer has shown that, in addition, vinylidine unsaturation ( R . R' /C=CH 2 ) is formed in the ratio of one vinylidene double bond to each chain fracture. The rate of main-chain fracture deduced from intrinsic viscosity measurements has been found to be initially (up to a dose of 35 Mrad) a function of the number of chain fractures produced, rather than proportional to the intensity of the radiation, as might have been expected from the behaviour of other polymers. After a dose of 50 to 60 Mrad an insoluble cross-linked gel can be separated from the polymer by solvent extraction, and the sol fraction decreases on further irradiation in accordance with the theoretical expression derived by Charlesby (1953), assuming that for every cross-link formed, one bond between two monomer units is broken. A mechanism for the radiation-induced changes is proposed, based upon the application of classical chemical kinetics, which is in good agreement with the observed phenomena.

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