Download or read book Effects of Neutron Irradiation and Thermal Annealing on Model Alloys Using Positron Annihilation Techniques written by AT. Motta and published by . This book was released on 2001 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a systematic investigation of neutron-irradiated and thermally annealed Fe-Cu-Ni-P model alloys using positron annihilation spectroscopy (PAS), including lifetime and Doppler broadening techniques, and Rockwell hardness. These alloys were examined in the as-fabricated state, after irradiation at 270° C to 1 x 1019 n.cm-2, and to 8 x 1019 n.cm-2, and after successive post-irradiation isochronal anneals at temperatures from 200 to 600° C. The results can be qualitatively explained by invoking an irradiation-induced microstructure consisting of a combination of small dislocation-type defects or defect clusters (matrix damage) and dense precipitation of fine scale irradiation-induced precipitates. The matrix damage anneals between 350° C and 450° C. The irradiation-induced precipitates also evolve with annealing, but at higher temperatures. The combined effect of high Cu and high Ni concentrations leads to more extensive irradiation-induced precipitation than in cases where either element is missing, whereas the effect of P is less pronounced. We analyze and compare the results with similar measurements performed on irradiated pressure-vessel steels and with other positron measurements on model alloys, reported in the literature.

Download or read book Annihilation of Positrons in Neutron Irradiated Metals and Alloys written by Ivaylo Mincov and published by LAP Lambert Academic Publishing. This book was released on 2010-09 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the recent years there is an increasing interest towards the positron annihilation spectroscopy as an examination technique in many fields of knowledge. Its basic applications are for scientific investigation in physics and materials science, because the method is non-destructive and very sensitive to different kinds of defects and phase transitions, but it found its place also in some practically aimed activities like medicine. In the present book are represented investigations of metals and alloys irradiated with 14 MeV generator neutrons. The investigated metals are of the most often used ones for the purposes of the nuclear reactor industry. The discussion goes mainly around the clusters formation in them as a result of neutron irradiation and their growing and disappearance in high temperature annealing. The methods of the positron spectroscopy, experimental setup used in the measurements and mathematical methods for data analysis are also mentioned. The obtained results may be very useful not only for scientists, but for all specialists in the field of nuclear energetics - projectors, constructors and nuclear engineers as well as for mechanical engineers and constructors.

Download or read book Effects of Radiation on Materials written by Stan T. Rosinski and published by ASTM International. This book was released on 2001 with total page 879 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Radiation Damage in Metals by Positron Annihilation Neutron Irradiation written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Positron annihilation is a sensitive technique for probing defects in metals and it has recently been shown to be a valuable tool for the study of radiation damage. After an introduction to the three basic experimental methods (angular correlation, Doppler broadening, and lifetime measurements), the interaction of positrons with lattice defects is reviewed. Results for the annealing of damage after low temperature irradiation are used to show that positron annihilation has provided new information on annealing kinetics. The role of positron techniques in characterizing complex defect structures resulting from high-temperature neutron irradiation is reviewed and the possible utility of positron annihilation as a nondestructive monitor of property changes is pointed out.

Download or read book Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application written by Congyi Li and published by . This book was released on 2018 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel Co-free NiFeMnCr HEA was synthesized for both ion and neutron irradiation studies. 3 and 5.8MeV heavy ion irradiations were conducted at room temperature and 400 - 700 °C from 0.03 to 10dpa. Post-irradiation examination included x-ray diffraction, nanoindentation hardness and transmission electron microscopy. The HEA exhibited quantitatively superior radiation resistance than conventional alloys, including suppressed void swelling and solute segregation. Neutron irradiation was conducted at 60 °C from 0.1 to 1dpa. Microhardness, electrical resistivity and positron annihilation spectroscopy measurements were performed at room temperature before and after isochronal annealing up to 700°C on the neutron-irradiated samples. The HEA retains fundamental stability after neutron irradiation. Compared with metals and conventional alloys, the HEA showed similar annealing trend of hardness and vacancy-type of defects. On the other hand, this HEA showed unique annealing trend of electrical resistivity. The large radiation induced resistivity increase (>10 [mu][Omega]·cm) did not recover up to 700 °C, suggesting short range ordering phenomena may be critical in radiation effects of HEA. In parallel, ab initio modeling was conducted to establish a solid foundation for multiscale modeling of HEA as well as to reveal unique defect physics of HEA. Magnetic structure was computed based on coherent potential. Vacancy energetics were computed by Vienna Ab initio Simulation Package (VASP). Modeling results shows that it is reasonable to neglect magnetic interactions. The statistical distribution of vacancy formation energy is weakly dependent upon either the chemical species of the atom site associated with the vacancy, or local chemical environment. The calculated migration energy values show a large spread, varying between 0.55 to 1.68eV, although the mean value is comparable to that of conventional austenitic alloys. Finally, positron lifetime of bulk HEA, mono-vacancy and small vacancy clusters were computed by a finite element based ab initio package to facilitate the interpretation of experimental results from positron annihilation spectroscopy.

Download or read book Report on the Effects of Neutron Radiation on Structural Materials written by M. Kangilaski and published by . This book was released on 1967 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Radiation on Materials written by and published by . This book was released on 2000 with total page 1296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Positron Annihilation written by and published by . This book was released on 1979 with total page 1008 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Proceedings of the Fifth International Conference on Positron Annihilation April 8 11 L979 Lake Yamanaka Japan written by Ryukiti R. Hasiguti and published by . This book was released on 1979 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ninth International Symposium on Environmental Degradation of Materials in Nuclear Power Systems written by Steve Bruemmer and published by John Wiley & Sons. This book was released on 2013-10-18 with total page 1776 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection presents an exchange of ideas among scientists and engineers about the economic and safety concerns surrounding environmentally induced materials problems which lead to nuclear power plant outages. Scientists and engineers concerned with the environmental degradation processes (corrosion, mechanical, and radiation effects) present their latest results on such topics as life extension/relicensing and materials problems associated with spent fuel storage and radioactive waste disposal. This collection will be of interest to utility engineers, reactor vendor engineers, plant architect engineers, researchers concerned with materials degradation, and consultants involved in design, construction, and operation of water reactors.

Download or read book Comprehensive Nuclear Materials written by and published by Elsevier. This book was released on 2020-07-22 with total page 4871 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials in a nuclear environment are exposed to extreme conditions of radiation, temperature and/or corrosion, and in many cases the combination of these makes the material behavior very different from conventional materials. This is evident for the four major technological challenges the nuclear technology domain is facing currently: (i) long-term operation of existing Generation II nuclear power plants, (ii) the design of the next generation reactors (Generation IV), (iii) the construction of the ITER fusion reactor in Cadarache (France), (iv) and the intermediate and final disposal of nuclear waste. In order to address these challenges, engineers and designers need to know the properties of a wide variety of materials under these conditions and to understand the underlying processes affecting changes in their behavior, in order to assess their performance and to determine the limits of operation. Comprehensive Nuclear Materials, Second Edition, Seven Volume Set provides broad ranging, validated summaries of all the major topics in the field of nuclear material research for fission as well as fusion reactor systems. Attention is given to the fundamental scientific aspects of nuclear materials: fuel and structural materials for fission reactors, waste materials, and materials for fusion reactors. The articles are written at a level that allows undergraduate students to understand the material, while providing active researchers with a ready reference resource of information. Most of the chapters from the first Edition have been revised and updated and a significant number of new topics are covered in completely new material. During the ten years between the two editions, the challenge for applications of nuclear materials has been significantly impacted by world events, public awareness, and technological innovation. Materials play a key role as enablers of new technologies, and we trust that this new edition of Comprehensive Nuclear Materials has captured the key recent developments. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environments Comprehensive resource for up-to-date and authoritative information which is not always available elsewhere, even in journals Provides an in-depth treatment of materials modeling and simulation, with a specific focus on nuclear issues Serves as an excellent entry point for students and researchers new to the field

Download or read book Metals Abstracts written by and published by . This book was released on 1993 with total page 606 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 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Irradiation of Pure Metals and Aluminum zinc Alloys written by James Albert Horak and published by . This book was released on 1966 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Nuclear Radiation on Structural Metals written by Frederic R. Shober and published by . This book was released on 1961 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of fast-neutron (>1 Mev) irradiation on the mechanical properties of structural metals and alloys was studied. Although the yield strengths and ultimate tensile strengths are increased su stantially for most materials, the ductility suffers severe decreases. This report presents these changes in properties of several structural metals for a number of neutron exposures within the 1.0 x 10 to the 18th power to 5.0 x 10 to the 21st power n/sq cm range. Data summarizing these effects on several classes of materials such as carbon steels, low-alloy steels, stainless steels, Zr-base alloys, ni-base alloys, Al-base alloys, and Ta are given. Additional data which show the influence f irradiation temperatures and of post-irradiation annealing on the radiation-induced property changes are also given and discussed. Increases as great as 175% in yield strength, 100% in ultimate strength, and decreases of 80% in total elongation are reported for fast-neutron exposures as great as 5 10 to the 21st power n/sq cm. (Author).