Download or read book Effects of Microstructural Factors on Irradiation Growth in Zirconium Niobium Alloys written by N. Sadaoka and published by . This book was released on 1989 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The irradiation growth mechanism of Zr-Nb alloys has been evaluated on the basis of a growth model in which point defect parameters obtained by molecular dynamics are used.

Download or read book An overview of microstructural and experimental factors that affect the irradiation growth behavior of zirconium alloys written by V. Fidleris and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Niobium on the Microstructural Evolution of Zirconium Alloys During Proton Irradiation written by Rebecca Jones and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Zirconium in the Nuclear Industry written by R. B. Adamson and published by ASTM International. This book was released on 1987 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Irradiation Induced Growth and Microstructure of Recrystallized Cold Worked and Quenched Zircaloy 2 NSF and E635 Alloys written by D. W. White and published by . This book was released on 2008 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper is devoted to the study of the effect of the texture, phase composition, and microstructure on the irradiation-induced growth strain (GS) of zirconium-based alloys. GS measurements and TEM microstructural examinations were performed on Zry-2, NSF, and E635 samples in the recrystallized, beta quenched and cold-worked (CW) conditions. The samples were irradiated in the BOR-60 reactor in the temperature range of 315-325°C up to a neutron fluence level of 1.1 x 1026 n/m2 (E>1MeV), i.e., up to a damage dose of 23 dpa. Growth strains of NSF and E635 alloys in all states and in the longitudinal and transverse directions are lower as compared to those of Zry-2, and do not exceed 0.2 % even at the maximum fluence level. As for recrystallized Zry-2, the GS kinetics are characterized by the appearance of the accelerated growth stage. A combination of a certain amount of Nb, Fe, and Sn in the matrix content plays a key role in GS kinetics. The higher the degree of CW, the higher the irradiation growth but its rate of increase with increasing fluence is different for alloys of different compositions. The maximum GS, reaching 0.72 %, is observed in the 20 % CW Zry-2 samples. Texture, along with the alloy composition, is one of the main GS-determining factors. Irradiation growth of the transversal samples is lower as compared to the longitudinal ones because of texture. As for quenched alloys, the texture is practically isotropic and GS values are low, independent of the alloy composition. In CW materials, the density of ‹c›- dislocations greatly affects the irradiation growth strain. Particles of Zr(Fe,Cr)2 and Zr2(Fe,Ni) phases in Zry-2 as well as Zr(Nb,Fe)2 in NSF and E635 are depleted in iron under irradiation. The Fe goes into the matrix and modifies its properties. The HCP lattice structure in the Laves phases in NSF and E635 changes into BCC (?-Nb-type). FCC (Zr,Nb)2Fe precipitates preserve on the whole their composition and structure; no amorphization of the Nb-containing precipitates is observed. The Zr2(Fe,Ni) precipitates with a BCT lattice remain crystalline, and HCP Zr(Cr,Fe)2 precipitates undergo amorphization. The average particle size in the irradiated alloys is larger and the concentration is a little lower as compared to the unirradiated ones. Irradiation-induced fine dispersed precipitates about 3 nm in size, probably enriched in niobium, appear in NSF and E635. The observed changes of microhardness are discussed from the viewpoint of generation of radiation defects (clusters, dislocation loops), evolution of the initial dislocation structure, and matrix composition (enrichment in Fe, Cr, and, probably, Nb).

Download or read book Zirconium in the Nuclear Industry written by Leo F. P. Van Swam and published by ASTM International. This book was released on 1989 with total page 781 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Influence of Zirconium Alloy Chemical Composition on Microstructure Formation and Irradiation Induced Growth written by AV. Tselischev and published by . This book was released on 2002 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies of the dislocation structure, phase, and microchemical compositions of alloy Zr-1Nb-1.2Sn-0.35Fe (E635) and its modifications containing Fe from 0.15 to 0.65% were carried out before and after research reactor irradiation at ~350°C to maximal fluence of ~1027 m-2 (E > 0.1 MeV) and at ~60°C. The size and concentration of the a-type loops depend on the alloy composition and fluence and saturate even at low doses (1 dpa). The evolution of the c-component dislocation structure in recrystallized alloys of E365 type is determined by the chemical and phase compositions of alloys specifically, by the Fe/Nb ratio and the threshold dose, and is consistent with the irradiation growth strain acceleration. In E635 alloy containing 0.15%Fe the accelerated growth is observed after the dose of 15 dpa and is attended with the evolution of the c dislocation structure which is similar to Zr-1Nb (E110) alloy behavior. The irradiation induced growth of E635 type alloy containing 0.65% Fe is similar to that of E635 having the normal composition; no

Download or read book Microstructure Evolution in Zr Alloys During Irradiation written by M. Griffiths and published by . This book was released on 2010 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of zirconium alloys in BWR, PWR, and PHWR nuclear reactors is dependent on the microstructure. Accordingly, the characterization of the microstructure is an integral part of any study conducted to develop models for in-reactor performance. Although the as-fabricated microstructure (texture, grain size, dislocation density, and phase or precipitate distribution) determines the basic physical properties of a given component, there are changes that occur during irradiation that can have a significant effect on these properties. Microstructures that illustrate specific features of the radiation damage that forms in Zr alloys will be illustrated and discussed in terms of the dose, dose rate, and impurity factors that are applicable. The original paper was published by ASTM International in the Journal of ASTM International, December 2007.

Download or read book Irradiation Growth of Zirconium Alloys written by JY. Ren and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental investigation of irradiation growth on annealed Zircaloy-4 and 20% to 50% cold-worked Zr-2.5wt%Nb specimens with stress relief has been carried out. The specimens are irradiated in a heavy water reactor at 610 K to 4.2 x 1024 n/m2 (E > 1.0 MeV). The growth strains increase linearly with fluence. The saturation of growth is not observed for all specimens. The difference of growth behavior between two kinds of Zircaloy-4 tube may be associated with the content of minor alloying elements and impurities that influence the microstructure evolution under irradiation.

Download or read book High Fluence Irradiation Growth of Zirconium Alloys at 644 to 725 K written by RB. Adamson and published by . This book was released on 1984 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Irradiation growth behavior of zirconium, Zircaloy-2 and Zircaloy-4,Zr-2.5Nb, and Zr-3.5Sn-0.8Mo-0.8Nb (EXCEL) was studied on specimens irradiated in the Experimental Breeder Reactor II (EBR-II) to fluences of 1.2 to 16.9 x 1025 neutrons (n).m-2 (E > 1 MeV) in the temperature range 644 to 725 K. In Zircaloy, growth and growth rate were observed to increase continuously with fluence up to 16.9 x 1025 n.m-2 with no indication of saturation in either recrystallized or cold-worked materials. Positive growth strains of 1.5% and negative strains of approximately 2% to 2.5% were observed in both recrystallized and cold-worked Zircaloy. The formation of both a-type loops and c component dislocations is recrystallized Zircaloy under irradiation appears to be the basis in this material for growth strains similar in magnitude to those in cold-worked Zircaloy. Alloy additions to zirconium can increase growth by as much as an order of magnitude for a given texture at the higher irradiation temperatures and fluences. A sharp change to increasing growth rate with temperature occurs in Zircaloy at ~670 K, with a similar trend indicated for the other alloys. Although growth in all these alloys is a strong function of crystallographic texture, an exact (1-3f) type of dependence is not always apparent. In Zr-2.5Nb the dependence of growth on texture appears to be masked by the precipitation of betaniobium, with a transition to a well-defined texture dependence being a function of fluence and temperature. Significant differences in growth behavior were observed in nominally similar Zircaloys, apparently due to minor microstructural or chemical differences.

Download or read book Microstructure and Properties of Zirconium Alloys in the Absence of Irradiation written by Daniel Charquet and published by . This book was released on 2010 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to optimize zirconium-based alloys, it is usually necessary to understand the relationships and interaction between four different types of parameters: chemical composition, manufacturing process, metallurgical characteristics, and functional properties Examples for various materials show that corrosion resistance depends on the texture and density, distribution, and composition of the precipitate particles. The precipitate composition is determined not only by the alloy chemistry, but also by other factors, such as the cooling rate from the beta phase range. It is also pointed out that some parameters can have opposite effets on nodular and uniform corrosion. Finally, the effects of some impurity elements are described, especially the effect of sulfur on creep and of chlorine on microstructure. The original paper was published by ASTM International in STP 1354, Zirconium in the Nuclear Industry: Twelfth International Symposium, 2000, pp. 314.

Download or read book Evolution of Microstructure in Zirconium Alloys During Irradiation written by M. Griffiths and published by . This book was released on 1996 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray diffraction (XRD) and transmission electron microscopy (TEM) have been used to characterize microstructural and microchemical changes produced by neutron irradiation in zirconium and zirconium alloys. Zircaloy-2, Zircaloy-4, and Zr-2.5Nb alloys with differing metallurgical states have been analyzed after irradiation for neutron fluences up to 25 x 1025 n.m-2 (E > 1 MeV) for a range of temperatures between 330 and 580 K.

Download or read book Peculiarities of Structural and Behavioral Changes of Some Zirconium Alloys at Damage Doses of Up to 50 Dpa written by VN. Shishov and published by . This book was released on 2004 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The irradiation-induced damage of zirconium alloys subjected to neutron irradiation up to dose levels of ~50 dpa was investigated. Specimens of unalloyed zirconium, Zr-1%Nb, Zr-2.5%Nb and Zr-1%Nb-1.3%Sn-0.4%Fe were irradiated in the BOR-60 reactor over the temperature range 320-420°C. The dose dependence of the irradiation growth strain increased sharply in zirconium and Zr-Nb irradiated at ~350°C at doses above ~10 dpa. In the case of Zr-1%Nb-1.3%Sn-0.4%Fe, it increased at doses of ~37 dpa. Upon increasing the irradiation temperature to 420°C, a sharp accelerated irradiation growth of the Zr-1%Nb alloy began shifting up to about 30 dpa. For the Zr- 1%Nb-1.3%Sn-0.4%Fe, no change of the irradiation growth rate was observed up to a dose of 55 dpa. The onset of increased irradiation growth in alloys correlates with the occurrence of c-component dislocation loops which coincides with a loss of coherence of finely-dispersed precipitates. Post-irradiation annealing experiments demonstrated that a delay in loop formation leads to displacement of the "break-away" beginning in the dose dependence of the irradiation growth in the direction of high doses. The a+c-type dislocation loops were also formed in Zr-1%Nb alloy at high doses, but their influence on the change of macroscopic properties was not observed.

Download or read book Microstructure dependence of irradiation Creep and growth of zirconium alloys written by R. A. Holt and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microstructural Effects on the Irradiation Growth of Zr 2 5Nb written by JD. Parker and published by . This book was released on 1987 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Irradiation growth tests at 553 K and a fast (E > 1.6 x 10-13 J) neutron flux of about 6.5 x 1017 n m-2s-1 were performed on specimens of Zr-2.5Nb pressure tubes to a neutron fluence of 3.5 x 1025 n m-2. The tubes were produced by different routes designed to change texture, grain shape, and dislocation density, but X-ray diffraction studies showed only minor changes in texture and dislocation density. However, electron microscopy revealed marked differences in dislocation substructure and second-phase distribution.

Download or read book Plastic Instability in Irradiated Zr Sn and Zr Nb Alloys written by BA. Cheadle and published by . This book was released on 1974 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Factors affecting the plastic instability of irradiated zirconium alloys in tensile deformation have been studied. The materials used were pure zirconium, commercial Zircaloy-2 and Zr-2.5Nb, and a series of alloys based on pure zirconium containing either niobium or tin. The materials were rolled into thick sheet which enabled different crystallographic textures and deformation modes to be studied. Niobium alloy additions delay the onset of plastic instability and in some circumstances reverse the textural effects found in commercial Zircaloy-2 and Zr-2.5Nb. The merits of Zr-Nb alloys for use as fuel sheathing are outlined.