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Molybdenum; Its Ores and their Concentration with a Discussion of Markets, Prices, and Uses

Description: From Scope and Purpose of Investigation: "The direct purpose of the bulletin is, on the one hand, to prove to possible consumers of molybdenum that the element is not as rare as commonly supposed, and that this country possesses many deposits of low-grade ore from which large supplies may be derived, and on the other hand, to prove to present and prospective producers of molybdenum that there is a latent market for their product in the alloy-steel trade, which needs only the assurance of steady supplies for a considerable development."
Date: 1916
Creator: Horton, Frederick W.
Partner: UNT Libraries Government Documents Department

The Climax Molybdenum Deposit, Colorado

Description: From abstract: The largest single metal-mining operation in the history of mining in Colorado has been developed at Climax, as a result of the increased use of molybdenum in the steel and other industries. Production of molybdenum at Climax was notable for a short period during the World War; it ceased from April 1919 to August 1924 but since then has shown a steady increase. In 1930 from 1,000 to 1,200 tons of ore was milled daily, using only one unit of the 2,000-ton mill. The mine has a reserve of broken ore sufficient to furnish 2,000 tons daily for 3 years and is being developed to continue to furnish this and a still further increased output as the use of the metal may warrant.
Date: 1933
Creator: Butler, B. S. & Vanderwilt, J. W.
Partner: UNT Libraries Government Documents Department

Colorimetric Determination of Molybdenum in TF₄

Description: The following report discusses a colorimetric method for molybdenum involving the reaction between a molybdate, thiocynate, and some reducing agent, usually SnCL2, that has been in use in the steel industry for some time.
Date: 1945
Creator: Wick, L. B.; Weaver, B. S. & Gates, J. W.
Partner: UNT Libraries Government Documents Department

Molybdenum and Tungsten Structural Differences are Dependent on ndz2/(n + 1)ѕ Mixing: Comparisons of (silox)3MX/R (M = Mo, W; silox = tBu3SiO)

Description: Article discussing molybdenum and tungsten structural differences being dependent on ndz2/(n + 1)s mixing and a comparison of (silox)3MX/R (M = Mo, W; silox - tBu3SiO).
Date: July 15, 2008
Creator: Kuiper, David S.; Douthwalte, Richard E.; Mayoi, Ana-Rita; Wolczanski, Peter T.; Lobkovsky, Emil B.; Cundari, Thomas R., 1964- et al.
Partner: UNT College of Arts and Sciences

Molybdenum: A Materials Survey

Description: Report issued by the U.S. Bureau of Mines discussing a survey conducted on molybdenum. History, geology, metallurgical properties, and production of molybdenum is presented. This report includes tables, illustrations, and maps.
Date: April 1957
Creator: McInnis, Wilmer & Creasey, S. C.
Partner: UNT Libraries Government Documents Department

Spreading of liquid Silver and Silver-Molybdenum alloys on molybdenum substrates

Description: The spreading of liquid Ag and Ag-Mo alloys on molybdenum substrates has been studied using a drop-transfer setup. Even though initial spreading velocities as fast as {approx}1 m/s have been recorded in some experiments, a large variation in the spreading dynamics has been observed, and there is no unique relationship between the contact angle and the spreading velocity. This can be attributed to the formation of ridges at the triple junction, the movement of which controls spreading. The fastest spreading rates are consistent with results reported for low temperature liquids; these can be described using a molecular-kinetic model. Spreading kinetics and final contact angles were similar for pure silver and silver-molybdenum liquids.
Date: August 1, 2002
Creator: Rauch, Nicole; Saiz, Eduardo & Tomsia, Antoni P.
Partner: UNT Libraries Government Documents Department

THE RADIOCHEMISTRY OF MOLYBDENUM

Description: A review of the nuclear and chemical features of particular interest to the radiochemist, a discussion of problems of dissolution of a sample and counting techniques, and a collection of radiochemical procedures for the elements as found in the literature are given. (W.L.H.)
Date: January 1, 1960
Creator: Scadden, E.M. & Ballou, N.E.
Partner: UNT Libraries Government Documents Department

Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum-rhenium Alloys

Description: Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt.%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt.% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt.% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14Re is greater than the base ODS molybdenum at 1,000 to 1,250 C.
Date: October 22, 1999
Creator: Mueller, A.J.; Bianco, R. & Buckman, R.W. Jr.
Partner: UNT Libraries Government Documents Department

Atomistic simulation of point defects and dislocations in bbc transition metals from first principles

Description: Using multi-ion interatomic potentials derived from first-principles generalized pseudopotential theory, we have been studying point defects and dislocations in bcc transition metals, with molybdenum (Mo) as a prototype. For point defects in Mo, the calculated vacancy formation and activation energies are in excellent agreement with experimental results. The energetics of six self-interstitial configurations in Mo have also been investigated. The <110> split dumb-bell is found to have the lowest formation energy, as is experimentally observed, but the corresponding migration energy is calculated to be 3--15 times higher than previous theoretical estimates. The atomic structure and energetics of <111> screw dislocations in Mo are now being investigated. We have found that the ``easy`` core configuration has a lower formation energy than the ``hard`` one, consistent with previous theoretical studies. The former has a distinctive 3-fold symmetry with a spread out of the dislocation core along the <112> directions, an effect which is driven by the strong angular forces present in these metals.
Date: January 19, 1996
Creator: Xu, W & Moriarty, J.A.
Partner: UNT Libraries Government Documents Department

Three-Dimensional Carbon Nanostructure and Molybdenum Disulfide (MoS2) for High Performance Electrochemical Energy Storage Devices

Description: My work presents a novel approach to fabricate binder free three-dimensional carbon nanotubes/sulfur (3DCNTs/S) hybrid composite by a facile and scalable method increasing the loading amount from 1.86 to 8.33 mg/cm2 highest reported to date with excellent electrochemical performance exhibiting maximum specific energy of ~1233Wh/kg and specific power of ~476W/kg, with respect to the mass of the cathode. Such an excellent performance is attributed to the fact that 3DCNTs offers higher loading amount of sulfur, and confine polysulfide within the structure. In second part of the thesis, molybdenum disulfide (MoS2) is typically studied for three electrochemical energy storage devices including supercapacitors, Li-ion batteries, and hybrid Li-ion capacitors. The intrinsic sheet like morphology of MoS2 provides high surface area for double layer charge storage and a layered structure for efficient intercalation of H+/ Li+ ions. My work demonstrates the electrochemical analysis of MoS2 grown on different substrates including copper (conducting), and carbon nanotubes. MoS2 film on copper was investigated as a supercapacitor electrode in three electrode system exhibiting excellent volumetric capacitance of ~330F/cm3 along with high volumetric power and energy density in the range of 40-80 W/cm3 and 1.6-2.4 mWh/cm3, respectively. Furthermore, we have developed novel binder-free 3DCNTs/ MoS2 as an anode materials in half cell Li-ion batteries. The vertically oriented morphology of MoS2 offers high surface area and active electrochemical sites for efficient intercalation of Li+ ions and demonstrating excellent electrochemical performance with high specific capacity and cycling stability. This 3DCNTs/ MoS2 anode was coupled with high surface area southern yellow pine derived activated carbon (SYAC) cathode to obtain hybrid 3DCNTs/ MoS2 || SYAC Li-ion capacitor (LIC), which delivers large operating voltage window of 1-4.0V with excellent cycling stability exhibiting capacitance retention of ~80% after 5000 cycles.
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Date: December 2017
Creator: Patel, Mumukshu D
Partner: UNT Libraries

In-situ Fracture Studies and Modeling of the Toughening Mechanism Present in Wrought LCAC, TZM, and ODS Molybdenum Flat Products

Description: In-situ testing, ultrasonic C-scans, and metallography were used to show that a crack-divider delamination form of thin-sheet toughening occurs in wrought Low Carbon Arc Cast (LCAC) unalloyed molybdenum, Oxide Dispersion Strengthened (ODS) molybdenum, and TZM molybdenum at temperatures {ge} the Ductile to Brittle Transition Temperature (DBTT). Cracking along boundaries relieves mechanical constraint to free ligaments that may plastically stretch to produce toughening. Anisotropy in fracture toughness with lower values in the short-transverse direction is shown to produce the crack divider delaminations at the crack tip in the LT and TL orientations. The delamination zone increases with increasing stress-intensity to sizes significantly larger than the plastic zone, which leads to large increases in fracture toughness by the thin sheet toughening mechanism. Fracture in ODS Mo-alloys proceeds mainly along grain boundaries to produce small ligaments that exhibit ductility for both LT and TL orientations resulting in a lower DBTT and higher toughness values at lower temperatures than observed in LCAC and TZM. A combination of grain boundary fracture and cleavage is prevalent in LCAC molybdenum and TZM. The predominance for microcracking along grain boundaries to leave fine, ductile ligaments in ODS molybdenum can be attributed to a fine-grained microstructure with {approx} 1-2 {micro}m thickness of sheet-like grains. The presence of mixed grain boundary fracture and cleavage in LCAC and TZM can be attributed to a microstructure with a larger thickness of sheet-like grains (4-15 {micro}m).
Date: July 1, 2007
Creator: Cockerman, B. V. and Chan, K. S.
Partner: UNT Libraries Government Documents Department

Oxide strengthened molybdenum-rhenium alloy

Description: Provided is a method of making an ODS molybdenum-rhenium alloy which includes the steps of: (1) forming a slurry containing molybdenum oxide and a metal salt dispersed in an aqueous medium, the metal salt being selected from nitrates or acetates of lanthanum, cerium or thorium; (2) heating the slurry in the presence of hydrogen to form a molybdenum powder comprising molybdenum and an oxide of the metal salt; (3) mixing rhenium powder with the molybdenum powder to form a molybdenum-rhenium powder; (4) pressing the molybdenum-rhenium powder to form a molybdenum-rhenium compact; (5) sintering the molybdenum-rhenium compact in hydrogen or under a vacuum to form a molybdenum-rhenium ingot; and (6) compacting the molybdenum-rhenium ingot to reduce the cross-sectional area of the molybdenum-rhenium ingot and form a molybdenum-rhenium alloy containing said metal oxide. The present invention also provides an ODS molybdenum-rhenium alloy made by the method.
Date: December 1, 1998
Creator: Bianco, Robert & Buckman, William R. Jr.
Partner: UNT Libraries Government Documents Department