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Preparation of Ductile Zirconium: Summary of Thermodynamic Data

Description: Abstract: A summary of thermodynamic calculations for zirconium halides is given. Data indicates that the iodide is the most promising of the halides for arc dissociation and that good recoveries of zirconium should be obtainable provided dissociation is carried out at reduced pressure.
Date: September 16, 1949
Creator: Findlay, G. R.
Partner: UNT Libraries Government Documents Department

The Ductility of Brazed Stainless Steel Joints

Description: Abstract: "The ductility of Type 310 stainless steel T-joints brazed with GE-62 brazing alloy was measured at room temperatures 1200, 1650, and 1800 F. The measure of ductility was taken as the plastic axial strain required to crack braze fillets in T-section tensile specimens. At elevated temperatures, the ductility of as-brazed joints approximated that of the stainless steel, but at room temperature the brazed joints had only one-tenth the ductility of the base metal. Annealing for 16 hr at 1800 F in air was found to triple the room-temperature ductility of the brazed joint."
Date: July 8, 1953
Creator: Saller, Henry A.; Stacy, J. T. & Eddy, N. S.
Partner: UNT Libraries Government Documents Department

A Model for Radiation Damaged Ductile Metals

Description: Abstract: "A model is presented for radiation damage to ductile metals that accounts qualitatively for the effects of radiation on the electrical and mechanical properties. The model consists of an agglomeration of interstitially displaced atoms into stacking faults in the lattice."
Date: June 10, 1953
Creator: Holden, A. N. & Kunz, F. W.
Partner: UNT Libraries Government Documents Department

Preparation of Ductile Zirconium: Progress Report for September 1949

Description: Abstract: A report was submitted describing the apparatus which is proposed for further dissociation experiments and approval for necessary construction was requested. While awaiting approval, detailed designs were completed and some experimental work necessary for this design was carried out. The casting equipment was modified in accordance with experimental work for casting of zirconium. The apparatus was tested and it was found possible to form and withdraw and ingot of zirconium.
Date: October 10, 1949
Creator: DiPietro, W. O.; Findlay, G. R. & Stauffer, R. A.
Partner: UNT Libraries Government Documents Department

Preparation of Ductile Zirconium: Progress Report for February 1950

Description: Abstract: A tungsten tipped electrode has been used in the continuous casting arc furnace for a 25 minute period during which a 12 inch length of ingot was made. Thermocouple junctions within the mold wall have been improved to give mold zone temperature. A total of 10 iodide dissociation runs have been conducted using feed rates of .62-22.7 lbs ZrI₄ per hour with attendant conversion efficiencies of 97.7-16.4% and zirconium yields of 255-41.2 grams per hour. A curve expressing these data for an arbitrarily selected set of conditions is presented.
Date: March 10, 1950
Creator: DiPietro, W. O.; Findlay, G. R. & Moore, J. H.
Partner: UNT Libraries Government Documents Department

Preparation of Ductile Zirconium: Progress Report for January 1950

Description: Abstract: A new feeder chute on the continuous casting apparatus, and the use of outgassed zirconium chips resulted in a stable arc and quiet pool. Ingots up to 9 1/2 inches in length were made, and some correlation between tension on the ingot and the "necking" effect was determined. Conversions of zirconium iodide to zirconium in the arc dissociation apparatus ran from 41 to 48.2 percent with a maximum of 474 grams of metal produced in 4 hours.
Date: February 10, 1950
Creator: DiPietro, W. O.; Findlay, G. R. & Moore, J. H.
Partner: UNT Libraries Government Documents Department

Strength and Ductility of Bainitic Steels

Description: Note presenting some of the factors believed to affect the strength and ductile-to-brittle transition temperature of bainitic steels, including mean ferrite path and degree of internal strain. Strength was measured by diamond pyramid hardness and transition temperature was obtained from a tensile impact test on small notched specimens. Results regarding strength and hardness of bainites, ductility (transition temperature) of bainite,
Date: August 1957
Creator: Desy, Donald H.; Brittain, J. O. & Gensamer, M.
Partner: UNT Libraries Government Documents Department

Elastic stability and the limit of strength

Description: The upper limit of strength (the ''theoretical strength'') has been an active subject of research and speculation for the better part of a century. The subject has recently become important, for two reasons. First, given recent advances in ab initio techniques and computing machines, the limits of strength can be calculated with considerable accuracy, making this one of the very few problems in mechanical behavior that can actually be solved. Second, given recent advances in materials engineering, the limits of strength are being approached in some systems, such as hardened or defect-free films, and their relevance is becoming recognized in others. The present paper discusses some interesting results from recent research on the limits of strength, with an intermixture of speculations based on those results. Topics include the inherent nature of {l_brace}100{r_brace} cleavage and ''pencil slip'' in bcc metals, the inherent ductility of fcc metals, the anomalous properties of Al, and the possibility of measuring ideal strength with nanoindentation.
Date: July 1, 2002
Creator: Morris Jr., J.W.; Krenn, C.R.; Roundy, D. & Cohen, Marvin L.
Partner: UNT Libraries Government Documents Department

Ductility Characterization of U-6Nb and Ta-W Alloys

Description: We have previously evaluated the ductility behaviors of U-6Nb and pure Ta. One important observation was that both alloys have very stable necking ductility independent of test conditions. In contrast, uniform ductility varied significantly depending upon strain rates and temperatures. In general, higher strain rate and lower temperature reduce the uniform ductility. Using literature data, we have developed two dynamic ductility models to predict the ductility behaviors of pure-Ta and water-quenched U-6Nb respectively under extreme conditions. In this study we further evaluate the aging effect on U-6Nb and the W-addition effect on Ta. For U-6Nb, the objective is to determine whether or not the ductility degradation by low-temperature aging mostly measured in quasi-static condition can still be observed under dynamic loading (high strain rate) condition. For Ta-W alloys, the focus is to identify the key control parameter so that the optimal condition of high-strength/high-ductility of Ta-10W can be achieved for certain defense-related applications.
Date: September 15, 2006
Creator: Sun, T & Cervantes, O
Partner: UNT Libraries Government Documents Department

CONSTRAINT EFFECT IN FRACTURE WHAT IS IT

Description: The meaning of the phrase 'constraint effect in fracture' has changed in the past two decades from 'contained plasticity' to a broader description of 'dependence of fracture toughness value on geometry of test specimen or structure'. This paper will first elucidate the fundamental mechanics reasons for the apparent 'constraint effects in fracture', followed by outlining a straightforward approach to overcoming this problem in both brittle (elastic) and ductile (elastic-plastic) fracture. It is concluded by discussing the major difference in constraint effect on fracture event in elastic and elastic-plastic materials.
Date: October 29, 2008
Creator: Lam, P & Prof. Yuh J. Chao, P
Partner: UNT Libraries Government Documents Department