Download or read book Mechanical Properties and Recrystallization Behavior of Electron beam melted Tungsten Compared with Arc melted Tungsten written by William D. Klopp and published by . This book was released on 1966 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study has been conducted of the properties of tungsten fabricated from three ingots consolidated by electron-beam melting. The study included purity as a function of number of melts, recrystallization a d grain growth behavior, low-temperature ductility, and high-temperature tensile and creep strength. The level of most metallic impurities in tungsten decreased with increasing number of electron-beam melts, the reduction being greatest for aluminum, iron, nickel, and silicon. The levels of interstitial impurities generally were not affected by remelting. Resistivity ratios for single crystals machined from ingot slices tended to increase on remelting. The recrystallization rates for worked, electron-beam- melted (EB-melted) tungsten were significantly higher than those observed earlier for arc-melted tungsten. The grain growth rates of EB-melted tungsten were higher than those reported previously for arc-melted tungsten, further reflecting the higher purity of the EB-melted materials. The activation energies for both recrystallization and grain growth in EB-melted tungsten were consistent with expected values assuming grain boundary self-diffusion to be the rate-controlling reaction. The ductile-brittle bend transition temperature for EB-melted tungsten is slightly higher in the worked condition than that reported for arc-melted tungsten. In the recrystallized conditions, the transition temperatures for EB- and arc-melted tungsten are similar. The tensile strength of EB-melted tungsten at 2500 to 4000 F is less than that of arc-melted tungsten. This is partly associated with the large grain size of EB-melted tungsten. However, when compared at the same grain size,
Download or read book Mechanical Properties and Recrystallization Behavior of Electron beam melted Tungsten Compared with Arc melted Tungsten written by William D. Klopp and published by . This book was released on 1966 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Alloying on Grain Refinement of Electron beam melted Tungsten written by Walter R. Witzke and published by . This book was released on 1966 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ingot structures resulting from electron-beam melting of tungsten consist mainly of columnar grains extending the length of the ingot. In order to examine the grain refining capabilities of various elemental and refractory compound additions, small ingots of tungsten containing these additions were prepared by electron-beam melting. Measurements on transverse ingot sections from each melt indicated that all the additions decreased the average grain diameter of the columnar grains typical of electron-beam melted tungsten and that grain refining effectiveness varied with the concentration of the solute S. Losses of the additions during melting were in excess of 90 percent in many cases. The most potent grain refiner was boron. A nominal addition of 0. 5 weight percent decreased the average grain diameter of the columnar grains from 0. 48 to 0. 008 centimeter. The effectiveness of the elemental additions decreased in the following order: boron, yttrium, carbon, hafnium, zirconium, molybdenum, columbium, rhenium, and tantalum. The losses of these elements during melting also decreased in approximately the same order. The elemental additions were generally more effective grain refiners than the refractory compounds. The elements with the smallest distribution coefficients were the most effective grain refiners.
Download or read book NASA Technical Note written by and published by . This book was released on 1966 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultra High Temperature Materials I written by Igor L. Shabalin and published by Springer. This book was released on 2014-05-16 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exhaustive work in three volumes with featuring cross-reference system provides a thorough overview of ultra-high temperature materials – from elements and chemical compounds to alloys and composites. Topics included are physical (crystallographic, thermodynamic, thermo-physical, electrical, optical, physico-mechanical, nuclear) and chemical (solid-state diffusion, interaction with chemical elements and compounds, interaction with gases, vapours and aqueous solutions) properties of the individual physico-chemical phases and multi-phase materials with melting (or sublimation) points over or about 2500 °C. The first volume focuses on carbon (graphite/graphene) and refractory metals (W, Re, Os, Ta, Mo, Nb, Ir). The second and third volumes are dedicated solely to refractory (ceramic) compounds (oxides, nitrides, carbides, borides, silicides) and to the complex materials – refractory alloys, carbon and ceramic composites, respectively. It will be of interest to researchers, engineers, postgraduate, graduate and undergraduate students in various disciplines alike. The reader is provided with the full qualitative and quantitative assessment for the materials, which could be applied in various engineering devices and environmental conditions at ultra-high temperatures, on the basis of the latest updates in the field of physics, chemistry, materials science, nanotechnology and engineering.
Download or read book A Selected Listing of NASA Scientific and Technical Reports for 1966 written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1967 with total page 2084 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Investigation of Melting Extruding and Mechanical Properties of Electron beam melted Tungsten written by Walter R. Witzke and published by . This book was released on 1963 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Purity and Structure on Recrystallization Grain Growth Ductility Tensile and Creep Properties of Arc melted Tungsten written by William D. Klopp and published by . This book was released on 1964 with total page 54 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 1974 with total page 1096 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fifth Status Report of the U S Government Metalworking Processes and Equipment Program written by F. C. Holden and published by . This book was released on 1966 with total page 76 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 1966 with total page 1466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Reports written by United States. National Aeronautics and Space Administration Scientific and Technical Information Division and published by . This book was released on 1967 with total page 2300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Selected Listing of NASA Scientific and Technical Reports for written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1966 with total page 2088 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by United States. Superintendent of Documents and published by . This book was released on 1966 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanical Properties of Dilute Tungsten rhenium Alloys written by William D. Klopp and published by . This book was released on 1966 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanical Properties of Solid solution and Carbide strengthened Arc melted Tungsten Alloys written by Peter L. Raffo and published by . This book was released on 1966 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government wide Index to Federal Research Development Reports written by and published by . This book was released on 1966 with total page 1336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
