Download or read book Void Formation in Some Nickel Aluminum Alloys During 20 MeV C and 46 5 MeV Ni6 Irradiation written by S. Francis and published by . This book was released on 1973 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The damage intensity along the ions track during 46.5-MeV Ni6+ irradiations of nickel and nickel-based alloys at void formation temperatures has been calibrated. Swelling versus depth profiles were determined in several nickel foils bombarded to a range of doses with 46.5 MeV Ni6+ at 525 C (977 F). A comparison of these results with previous data on swelling in nickel after 20 MeV C++ irradiation at this temperature was made to calibrate the Ni6+ irradiations.

Download or read book Effects of Radiation on Substructure and Mechanical Properties of Metals and Alloys written by John Moteff and published by ASTM International. This book was released on 1973 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Effects and Tritium Technology for Fusion Reactors written by and published by . This book was released on 1976 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Radiation on Substructure and Mechanical Properties of Metals and Alloys written by and published by . This book was released on 1973 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Void Swelling and Segregation in Dilute Nickel Alloys 3 5 MeV 58Ni Irradiation written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Five binary alloys containing 1 at.% of Al, Ti, Mo, Si and Be in nickel were irradiated at temperatures from 525 to 675°C with 3.5-MeV 58Ni ions. The resultant microstructures were examined by TEM, and void diameters, number densities and swelling are presented for each alloy over the temperature interval investigated. A systematic relation between solute misfit (size factor) and void swelling is established for these alloys. Solute concentration profiles near the irradiated surface were determined and these also exhibited a systematic behavior--undersize solutes segregated to the surface, whereas oversize solutes were depleted. The results are consistent with calculations based on strong interstitial-solute trapping by undersize solutes and vacancy-solute trapping by oversize solutes that are weak interstitial traps.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Voids in Neutron Irradiated Aluminum written by Nicolas Hayes Packan and published by . This book was released on 1970 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Void formation in high purity aluminum resulting from irradiation to fluences between 1.5 x 1019 and 1.6 x 1022 neutrons/cm2 (E> 0 .1 MeV) at a temperature of 55 ± 5°C was studied, primarily by means of transmission electron microscopy. In particular the effects of neutron fluence and flux were examined, as well as the possible influences of both preexisting and transmutation-produced impurities. A very low concentration of voids (about 1012 /cm3) resulted from irradiation to 1.5 x 1019 neutrons/cm2; they averaged about 150 Å in diameter. Void concentrations and sizes increased with fluence, reaching values of 6 x 1014 voids/cm3 averaging 500 Å in diameter at 1.6 x 1022 neutrons/cm2. Void formation initially was nonuniform in distribution, but tended to be homogeneous at higher fluences. The void shapes were always consistent with those of octahedra bounded by {111} planes, sometimes with the vertices truncated by {100} planes. Void size distribution curves were obtained for all fluences, and from these the mean void size was found to increase in proportion to the fluence raised to the one-sixth power. The void concentration displayed a fluence dependence best described by a power law, N ~ ([phi]t)[superscript a], in which the exponent decreased from 2 at 1.5 x 1019 neutrons/cm2 (E> 0.1 MeV) down to only 0.1 at 1.6 x 1022 neutrons/cm2. Treating the swelling with a similar power law, [delta]V/V ~ ([phi]t)[superscript b], a similar saturation effect was observed, with the fluence exponent b[underlined] decreasing roughly from 2.5 to 0.5 over the range of fluence studied. At 1.6 x 1022 neutrons/cm2 the total void volume or swelling amounted to 7.4%. Microhardness increases in the irradiated specimens can be explained on the basis of void contributions to the impeding of dislocation motions. Irradiation at a factor-of-ten lower flux produced effects upon the void morphology (e.g ., half as many but larger and more elongated voids) much like those resulting from irradiation at a higher temperature. In each case, the lowering of the vacancy supersaturation during irradiation is a consequence. Irradiation, annealing to remove damage, and reirradiation of a specimen, each exposure to a fluence of 5 x 1020 neutrons/cm2 (E> 0.1 MeV), yielded twice as many voids of smaller maximum size, having the same total void volume as those produced by the first irradiation alone. The effect is attributed to submicroscopic remnants of the original voids surviving the anneal and serving as preexisting nuclei in the second irradiation. In postirradiation void annealing experiments performed inside a high vacuum electron microscope, the rate at which void radius changed, dr/dt, varied considerably from void to void. A transient effect in dr/dt was observed upon abrupt changes in the annealing temperature. Both effects are ascribed to the actions of local vacancy sinks near the voids, such as a suggested population of submicroscopic gas bubbles. The experimental observations are compared with the current models for void formation. The two models most consistent with the experimental evidence both involve transmutation-produced helium playing a crucial role in void nucleation--one involving helium-stabilized spikes and the other small helium bubbles as the nuclei of voids. Throughout this work effects were found which demonstrate a strong influence of impurities upon void formation in high purity aluminum"--Abstract, leaves ii-iv.

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1976 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Nickel and Nitrogen on Void Formation in Vanadium written by Randy George Lott and published by . This book was released on 1979 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nucleation Growth and Distribution of Cavities in the Vicinity of Grain Boundaries in Aluminum Irradiated with 600 MeV Protons written by WV. Green and published by . This book was released on 1987 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-purity aluminum (99.9999%) was irradiated with 600-MeV protons with a damage rate of 3.5 x 10-6 dpa/s and a helium generation rate of 214 atomic parts per million (appm) per dpa. The irradiation experiments were carried out at temperatures in the range 120 to 140°C to doses up to 5 dpa. Transmission electron microscopy on irradiated specimens showed that voids are formed only in a narrow band in the vicinity of the void denuded zone along grain boundaries. Both the density and the size of voids in this band vary as a function of distance from the denuded zone. Changes in irradiation dose and temperatures do not seem to affect the spatial distribution of voids in the band. These results are compared with the results obtained on high-purity aluminum irradiated with fast neutrons. The bubble formation behavior in the grain interior and in the band containing voids is briefly described. The effect of bubble formation on the growth behavior of voids is discussed.

Download or read book Metals Abstracts written by and published by . This book was released on 1980 with total page 1488 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1977 with total page 1118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Void Formation and Solute Segregation in Ion irradiated Niobium base Alloys written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The void-volume fraction in unalloyed Nb and Nb-base binary alloys containing either approx. 2.4 a/o Mo, Ti, Zr, Hf, Ni, Fe, V, or Ta has been determined following 3.0-MeV 58Ni/sup +/ ion irradiation at 1225 K to approx. 50 dpa. also, the thermal- and irradiation-induced segregation of these substitutional-atom solutes and the intrinsic, interstitial-O impurity (approx. 0.06 a/o) to the specimen surface and within the irradiation-damaged layer have been determined. The void-volume fraction and the segregation of solutes have been shown to be correlated by the solute diffusivity and the relative chemical affinity of the substitutional solutes for O. The correlated diffusion of vacancy defects and O atoms is postulated to explain the experimental results.

Download or read book Ion solid Interactions Bibliography written by Walter M. Gibson and published by . This book was released on 1980 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book INIS Atomindex written by and published by . This book was released on 1977 with total page 1096 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Defect Formation in 800 MeV Proton irradiated Aluminum written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission electron microscopy was used to investigate the formation of irradiation-induced defects in proton-irradiated high-purity aluminum. The specimens were irradiated by 800-MeV protons to about 0.25 displacements per atom (dpa) in the Los Alamos Meson Physics Facility (LAMPF), producing about 20 atomic ppM helium, 130 atomic ppM hydrogen, and approximately 70 atomic ppM of spallation products. The as-irradiated microstructure mainly consisted of cavities with a mean size of 88 A, number density of 1 x 1015 cavities/cm3, and volume fraction of about 0.05%. The swelling was comparable to that of high-purity aluminum samples neutron-irradiated to the same displacement level. However, the high production rate of gas atoms during the proton irradiation increased the cavity number density by an order of magnitude relative to neutron irradiation, and reduced the cavity size by a factor of about 3. A postirradiation annealing treatment at 250°C resulted in complete disappearance of the small cavities and formaion of gas bubbles on grain boundaries.