Download or read book Electron Microscopy of Precipitation and Age Hardening in Fe 0 6Cu Model Alloy written by H. Kawanishi and published by . This book was released on 1999 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional electron microscopy was done on thermally-aged Fe-0.6 wt.% Cu alloy to study the precipitation behavior of copper in ?-iron. The alloy was aged at 500°C for 1000 h after water-quenching at 850°C. Transmission electron microscopy observations showed that the disk-shaped copper precipitate of a fcc-structure and ~0.4 nm in thickness was formed with water-quenching, where there was a Kurdjumov-Sachs orientation relation between the precipitate and the matrix. Aging was proved to reduce the density and diameter of the precipitates and to increase their thickness. Peak hardness was achieved at 100 h-aging. The precipitate was identified to be still disk-shaped (~2 nm in thickness and ~7 nm in diameter) and coherent with the matrix after 1000 h-aging.
Download or read book Precipitation strengthed i e Strengthened Austentic Fe Mn Ti Alloys written by Keh-Minn Chang and published by . This book was released on 1977 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructure and Hardening in Thermally Aged and Neutron Irradiated Fe Cu Model Alloy written by M. Suzuki and published by . This book was released on 2000 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructure of Fe-0.6 wt.% Cu alloys irradiated at 290°C to 0.0055 dpa in the Japan Materials Testing Reactor was examined using a conventional electron microscopy technique to study the precipitation behavior of copper in ?-iron, in addition to those thermally aged at 500°C for 1000 h and unalloyed Fe. Hardness measurements were also carried out. Results showed that there were two kinds of copper precipitates in thermally aged alloys. The first one was an ultrathin untwinned precipitate that increased in thickness with aging, decreasing in size and number density. The second was small with twinning, that grew little until peak hardness. Age hardening, thus, was attributed to ultrathin copper precipitate. Irradiation, which induced a dramatic hardening in the alloys, eliminated the ultrathin precipitates while the small-twinned ones survived. Two (111) patterns appeared on a (110) selected area diffraction pattern of the ?-iron matrix in the irradiated specimens with one (111) pattern analyzed to be due to (110)Cu3Fe reflections (forbidden reflections in fcc crystals) and the other (111) pattern to (220)Fe3O4 reflections. It was concluded that irradiation induced the formation of short range ordered domains of Cu3Fe-superlattice (L12-type) in Fe-Cu alloys, resulting in the dramatic hardening. The precipitation of FeSi was recognized to be enhanced by irradiations in unalloyed iron.
Download or read book Precipitation in an Aged Fe 0 85 At Cu Alloy Observed by Muon Spin Rotation Spectroscopy written by Ulrich Zimmermann and published by . This book was released on 1990 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first muon spin rotation study of the precipitation in Fe(Cu) alloys is presented. The precipitation was induced by a series of isochronal (1-h) annealing steps at temperatures T? between 460°C and 660°C and monitored by electron microscopy and hardness measurements; particle size and density for the early stage were also estimated by classical nucleation theory. The advance of phase separation appears in the muon signal in two ways. At the early stage, with small particles and a low precipitated solute fraction, the depolarization rate rises and peaks at T?=540°C, whereas the depletion in solute of the matrix and the commencement of ripening is revealed by a rapid change in the precession frequency, going through a maximum at T?=580°C. The method is sensitive at relatively low measuring temperatures (180 to 230 K). All these features could be interpreted in terms of precipitate size and density, taking into account the role of the "free diffusion length" of the implanted muons in the sample. Aspects of future application of the method in the study of neutron irradiated iron and iron-based alloys are also discussed.
Download or read book Hardening Characteristics of Ion Irradiated Iron Based Model Alloys written by Y. Arai and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fe-C-Cu, Fe-C-Ni, and Fe-C-Cu-Ni model alloys were prepared in order to investigate the effects of copper and nickel on radiation embrittlement. They were irradiated with 4 MeV Ni3+ ions at 563 K to introduce displacement damage, followed by a micro-Vickers hardness test employing low load (0.5 g). It was observed that greater hardening occurred for samples of larger copper content, and that hardening of the samples containing both copper and nickel was greater than hardening of the ones containing copper or nickel solely for samples irradiated to 10-2 and 10-1 dpa. Increased hardness after annealing occurred for Fe-0.1C-0.2Cu and Fe-0.lC-0.4Cu. Small defect clusters of approximately 3 nm in diameter were observed by transmission electron microscopy (TEM) of the irradiated Fe-0.1C and Fe-0.1C-0.4Cu samples, which cause hardening.
Download or read book Correlative Microscopy of alpha Prime Precipitation in Neutron irradiated Fe Cr Al Alloys written by Samuel Austin Briggs and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fe-Cr-Al alloys are currently being considered for accident tolerant light water reactor fuel cladding applications due to their superior high temperature oxidation and corrosion resistance compared to Zr-based alloys. However, precipitation of the Cr-rich [alpha prime] phase during exposure to LWR operational environments can result in application-limiting hardening and embrittlement. To study this effect, four Fe-Cr-Al model alloys with compositions between 10-18 at.% Cr and 5.8-9.3 at.% Al have been neutron-irradiated in the High Flux Isotope Reactor at a target temperature of 320°C to nominal damage doses of up to 7 dpa in order to emulate typical LWR exposure conditions. A correlative microscopy approach involving atom probe tomography, small-angle neutron scattering, and scanning transmission electron microscopy coupled with energy dispersive x-ray spectroscopy was employed to study the resulting precipitate microstructure. This approach necessitated the development of various analysis techniques to allow for cross-comparison between experimental techniques, including a novel method for correcting for trajectory aberration artifacts in atom probe data sets through phase density comparison. Successful correlation of results from these techniques allows for the individual limitations of each to be overcome and enables the detailed microstructural information gleaned from highly localized atom probe tomography analyses to be extrapolated to bulk alloy behavior. Precipitation response was found to increase with Cr content, while Al additions appeared to partially destabilized the [alpha prime] phase, resulting in precipitate compositions with reduced Cr content compared to binary Fe-Cr systems. Observed precipitate evolution with radiation dose indicates a diffusion-limited coarsening mechanism that is similar to what is observed in the thermally aged system. This work represents the current state-of-the-art on both techniques for analysis of [alpha prime] precipitate microstructures and the processes and mechanisms governing its formation in neutron-irradiated Fe-Cr-Al alloys.
Download or read book Electron Microscopy of Thermally Aged FeCu and FeCuNi Model Alloys written by J. T. Buswell and published by . This book was released on 1987 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Group Precipitation and Age Hardening of Nanostructured Fe based Alloys with Ultra high Strengths written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. Lastly, the co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.
Download or read book A Microstrain and Transmission Electron Microscopy Investigation of the Precipitation Hardening Alloy Cu 1 8O Wt Be O 28 Wt Co written by B. C. Edwards and published by . This book was released on 1971 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Electron Microscopic Investigation of Precipitation Hardening in Copper rich Cu cr and Cu zr Alloys written by Timothy Newell Taylor and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structure and Hardening Mechanism of Copper Precipitation in Thermally Aged Or Irradiated Fe Cu and Fe Cu Ni Model Alloys written by JT. Buswell and published by . This book was released on 1992 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reactor pressure vessel of a pressurized water reactor can be embrittled by neutron irradiation from the core It has been recognized for many years that copper plays a significant role in the embrittlement process and more recently that copper precipitates pin dislocations In developing fundamental understanding and mechanistic models to predict embrittlement, it is important to identify the microscopic mechanisms underlying this phenomena Although considerable progress has been made recently on characterizing the irradiation-produced microstructure, relatively little is known about the nature, morphology, and composition of the copper precipitates or the atomic processes whereby they pin dislocations The purpose of this paper is to discuss recent results from experimental studies and computer modelling of the properties of the copper precipitates formed after irradiating or thermally aging model Fe-Cu and Fe-Cu-Ni alloys.
Download or read book Precipitation Hardening in an Fe 5 Ni 1 2 Al Alloy written by Robert B. Dixon and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Age Hardening of a Fe Mn Al Alloy written by Hsin-Min Chen and published by . This book was released on 1994 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1989-07 with total page 1494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book World Aluminum Abstracts written by and published by . This book was released on 1972 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1989-07 with total page 1314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Casting Aluminum Alloys written by Michael V Glazoff and published by Elsevier. This book was released on 2010-07-07 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: Casting Aluminum Alloys summarizes research conducted at Moscow Institute of Steel and Alloy during many decades in part together with Alcoa Inc. The research covered areas of the structure, properties, thermal resistance, corrosion and fatigue of aluminum alloys in industrial manufacturing. - Emphasis on interconnection among phase equilibria, thermodynamics and microstructure of alloys - Systematic overview of all phase diagrams with Al that are important for the development of casting aluminium alloys - Diagrams ("processing windows") of important technological properties such as castability, molten metal fluidity, tendency to hot pre-solidification cracking, porosity - Mathematical models for alloy mechanical properties facilitating the down-selection of best prospect candidates for new alloy development - New principles of design of eutectic casting aluminium alloys - Examples of successful novel casting alloy development, including alloys for high-strength applications, alloys with transition metals, and novel alloys utilizing aluminium scrap
