Download or read book Fundamental Investigations of High temperature Creep of a Particle strengthened Niobium Alloy written by David Michael Farkas and published by . This book was released on 1995 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamental Investigations of Creep and Fatigue of Dispersion Strengthened Nb Alloys written by and published by . This book was released on 1995 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the three years of this program, the creep studies focused on a select precipitation strengthened alloy of niobium shown to possess superior creep resistance at stress levels normally targeted in design applications. The alloy selected was a carbide precipitation strengthened niobium-zirconium-alloy (Nb-1wt%Zr-0.1wt%C) commercially known as PWC-11. The carbide precipitations are produced in-situ during the thermomechanical processing of the material and have proven to be extremely stable at service temperature. Transmission electron microscopy was used to examine both the internal structure of the crept material as well as the size distribution of the carbide particles extracted from the metal matrix. X-ray diffraction analysis of the extracted carbide particles identified their chemical make-up necessary for characterizing their thermodynamic stability. A thermodynamic model was developed which supports the observed parameters of the carbide precipitates and thus is useful in predicting the high temperature mechanical properties of this and similar alloy systems. jg p1.

Download or read book Creep Strength of Niobium Alloys Nb 1 zr and Pwc 11 written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-29 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study is being conducted at NASA Lewis Research Center to determine the feasibility of using a carbide particle strengthened Nb-1 percent Zr base alloy to meet the anticipated temperature and creep resistance requirements of proposed near term space power systems. In order to provide information to aid in the determination of the suitability of the PWC-11 alloy as an alternative to Nb-1 percent Zr in space power systems this study investigated: (1) the long-time high-vacuum creep behavior of the PWC-11 material and the Nb-1 percent Zr alloy, (2) the effect of prior stress-free thermal aging on this creep behavior, (3) the effect of electron beam (EB) welding on this creep behavior, and (4) the stability of creep strengthening carbide particles. Titran, Robert H. Glenn Research Center NASA-TM-102390, E-5102, DOE/NASA/16310-13, NAS 1.15:102390 DE-AI03-86SF-16310; RTOP 586-01-11...

Download or read book High Temperature Strain of Metals and Alloys written by Valim Levitin and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Creep and fatigue are the most prevalent causes of rupture in superalloys, which are important materials for industrial usage, e.g. in engines and turbine blades in aerospace or in energy producing industries. As temperature increases, atom mobility becomes appreciable, affecting a number of metal and alloy properties. It is thus vital to find new characterization methods that allow an understanding of the fundamental physics of creep in these materials as well as in pure metals. Here, the author shows how new in situ X-ray investigations and transmission electron microscope studies lead to novel explanations of high-temperature deformation and creep in pure metals, solid solutions and superalloys. This unique approach is the first to find unequivocal and quantitative expressions for the macroscopic deformation rate by means of three groups of parameters: substructural characteristics, physical material constants and external conditions. Creep strength of the studied up-to-date single crystal superalloys is greatly increased over conventional polycrystalline superalloys. From the contents: - Macroscopic characteristics of strain at high temperatures - Experimental equipment and technique of in situ X-ray investigations - Experimental data and structural parameters in deformed metals - Subboundaries as dislocation sources and obstacles - The physical mechanism of creep and the quantitative structural model - Simulation of the parameters evolution - System of differential equations - High-temperature deformation of industrial superalloys - Single crystals of superalloys - Effect of composition, orientation and temperature on properties - Creep of some refractory metals For materials scientists, solid state physicists, solid state chemists, researchers and practitioners from industry sectors including metallurgical, mechanical, chemical and structural engineers.

Download or read book Creep Strength of Niobium Alloys Nb 1 Zr and PWC 11 written by and published by . This book was released on 1990 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study is being conducted at NASA Lewis Research Center to determine the feasibility of using a carbide particle strengthened Nb-1% Zr base alloy to meet the anticipated temperature and creep resistance requirements of proposed near term space power systems. In order to provide information to aid in the determination of the suitability of the PWC-11 alloy as an alternative to Nb-1% Zr in space power systems this study investigated (1) the long-time high-vacuum creep behavior of the PWC-11 material and the Nb-1% Zr alloy, (2) the effect of prior stress-free thermal aging on this creep behavior, (3) the effect of electron beam (EB) welding on this creep behavior, and (4) the stability of creep strengthening carbide particles. 14 refs., 5 figs., 2 tabs.

Download or read book Dispersion Strengthening of High Temperature Niobium Alloys written by D. L. Anton and published by . This book was released on 1988 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Niobium base alloys are very attractive as high temperature materials for advanced gas turbine applications. After many conventional metallurgical approaches, a high temperature creep resistant alloy has yet to be identified which will replace nickel base superalloys. The best chance for obtaining high temperature creep resistance in these alloys is through dispersion strengthening with a stable precipitate that is introduced through rapid solidification. This would result in a very fine dispersion of nonshearable precipitates that would not coarsen upon long term exposure at temperatures in excess of 1200 C.A study has been conducted here to identify such a stable dispersion, fabricate alloys through solidification approach and characterize the coarsening of the resulting precipitates. A thermodynamic argument is presented to select candidate dispersions for evaluation. Arc melted and splat quenched alloys were fabricated and evaluated through micro-hardness measurements. An indirect assessment of particle stability is introduced which resulted in a coarsening parameter determined for each candidate precipitate at 1400 C. Microscopic examination of the more stable alloys were made via optical and thin foil TEM analyses. Tensile and strain-rate sensitivity tests were run on these alloys at 1400 C. Niobium, Dispersion strengthening, High temperature strength, Particle coarsening, Refractory metals, Niobium alloys. (jes).

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 1118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Niobium Alloys written by Minerals, Metals and Materials Society. Fall Meeting and published by Minerals, Metals, & Materials Society. This book was released on 1991 with total page 180 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 1972-04 with total page 1068 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Creep in Metals and Alloys written by Michael E. Kassner and published by Elsevier. This book was released on 2004-04-06 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: * Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials * Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures * Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussionUnderstanding the strength of materials at a range of temperatures is critically important to a huge number of researchers and practitioners from a wide range of fields and industry sectors including metallurgists, industrial designers, aerospace R&D personnel, and structural engineers. The most up-to date and comprehensive book in the field, Fundamentals of Creep in Metals and Alloys discusses the fundamentals of time-dependent plasticity or creep plasticity in metals, alloys and metallic compounds. This is the first book of its kind that provides broad coverage of a range of materials not just a sub-group such as metallic compounds, superalloys or crystals. As such it presents the most balanced view of creep for all materials scientists. The theory of all of these phenomena are extensively reviewed and analysed in view of an extensive bibliography that includes the most recent publications in the field. All sections of the book have undergone extensive peer review and therefore the reader can be sure they have access to the most up-to-date research, fully interrogated, from the world's leading investigators.· Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials· Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures· Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussion

Download or read book Materials Transactions JIM written by and published by . This book was released on 2002 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Creep and High Temperature Deformation of Metals and Alloys written by Stefano Spigarelli and published by MDPI. This book was released on 2019-12-12 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: By the late 1940s, and since then, the continuous development of dislocation theories have provided the basis for correlating the macroscopic time-dependent deformation of metals and alloys—known as creep—to the time-dependent processes taking place within the metals and alloys. High-temperature deformation and stress relaxation effects have also been explained and modeled on similar bases. The knowledge of high-temperature deformation as well as its modeling in conventional or unconventional situations is becoming clearer year by year, with new contemporary and better performing high-temperature materials being constantly produced and investigated. This book includes recent contributions covering relevant topics and materials in the field in an innovative way. In the first section, contributions are related to the general description of creep deformation, damage, and ductility, while in the second section, innovative testing techniques of creep deformation are presented. The third section deals with creep in the presence of complex loading/temperature changes and environmental effects, while the last section focuses on material microstructure–creep correlations for specific material classes. The quality and potential of specific materials and microstructures, testing conditions, and modeling as addressed by specific contributions will surely inspire scientists and technicians in their own innovative approaches and studies on creep and high-temperature deformation.

Download or read book Strengthening Mechanisms Creep and Fatigue Processes in Dispersion Hardened Niobium Alloy written by and published by . This book was released on 1992 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The creep and fatigue properties of pure Nb and Nb-l%Zr alloy were investigated. A model was developed based on the migration of subgrain boundary that can explain the anomalous primary creep transients found in Nb-l%Zr alloy, due to coarsening of subgrain structure. TEM investigations confirmed that such subgrain coarsening occurs during primary creep of Nb-l%Zr. Baseline low cycle fatigue studies of Nb and Nb-l%Zr were completed. Cyclic hardening is observed and there is a microplastic plateau in Nb. The Nb-1%Zr is stronger in cyclic deformation than Nb, with little influence of strain rate. The deformation in the alloy at both high and low strain rates is controlled by the interaction between gliding edge dislocation and solute atoms. Creep, fatigue, niobium alloy, dislocation mechanisms.

Download or read book High Temperature Creep Behavior of Second phase Particle Strengthened Tungsten rhenium Alloys written by Bor-liang Chen and published by . This book was released on 1990 with total page 366 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 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The High Temperature Creep of Niobiumoxygen and Niobium carbon Alloys written by J. D. W. Rawson and published by . This book was released on 1965 with total page 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 1994 with total page 1256 pages. Available in PDF, EPUB and Kindle. Book excerpt: