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Extrusion Die Design : [bibliography]

Description: "This is a selective bibliography of books and periodical articles relating to extrusion die design with special emphasis on extrusion of beryllium. Material on the extrusion process has been included when it contains information that might be of possible help in die designing."
Date: April 23, 1957
Creator: Cason, Maggie
Partner: UNT Libraries Government Documents Department

Die Design for Hot Presses ; [Bibliography]

Description: Abstract: "This is a selective bibliography of books and periodical articles relating to die design of hot presses. Sources consulted include: ASM Review of Metal Literature, 1950-1954; Chemical Abstracts, 1950-1055; Engineering Index, 1950-1055; Industrial Arts Index, 1950-March 1957; Metallurgical Abstracts, 1950-1953; Nuclear Science Abstracts, 1950-March 1957; Physics Abstracts, 1950-1955; the library card catalog, and the Technical Information Division AEC card catalog."
Date: April 19, 1957
Creator: U.S. Atomic Energy Commission
Partner: UNT Libraries Government Documents Department

A Comparative Analysis of the "Dies Irae" in Mozart's Requiem and Cherubini's Requiem in D Minor

Description: The thesis speculates on the possible influence of Mozart's Requiem on Cherubini's Requiem in D Minor, concluding that Cherubini's setting of the Sequence ("Dies irae") was indeed influenced by Mozart's setting of this liturgical text both on the micro and macro levels.
Date: August 1997
Creator: Leong, Jeremy
Partner: UNT Libraries

Chemical strategies for die/wafer submicron alignment and bonding.

Description: This late-start LDRD explores chemical strategies that will enable sub-micron alignment accuracy of dies and wafers by exploiting the interfacial energies of chemical ligands. We have micropatterned commensurate features, such as 2-d arrays of micron-sized gold lines on the die to be bonded. Each gold line is functionalized with alkanethiol ligands before the die are brought into contact. The ligand interfacial energy is minimized when the lines on the die are brought into registration, due to favorable interactions between the complementary ligand tails. After registration is achieved, standard bonding techniques are used to create precision permanent bonds. We have computed the alignment forces and torque between two surfaces patterned with arrays of lines or square pads to illustrate how best to maximize the tendency to align. We also discuss complex, aperiodic patterns such as rectilinear pad assemblies, concentric circles, and spirals that point the way towards extremely precise alignment.
Date: September 1, 2010
Creator: Martin, James Ellis; Baca, Alicia I.; Chu, Dahwey & Rohwer, Lauren Elizabeth Shea
Partner: UNT Libraries Government Documents Department

Solid explosive plane-wave lenses pressed-to-shape with dies

Description: Solid-explosive plane-wave lenses 1", 2" and 4¼" in diameter have been mass-produced from components pressed-to-shape with aluminum dies. The method used to calculate the contour between the solid plane-wave lens components pressed-to-shape with the dies is explained. The steps taken to press, machine, and assemble the lenses are described. The method of testing the lenses, the results of those tests, and the corrections to the dies are reviewed. The work on the ½", 8", and 12" diameter lenses is also discussed.
Date: November 1, 2007
Creator: Olinger, B.
Partner: UNT Libraries Government Documents Department

Oral History Interview with Martin Dies, April 23, 1966

Description: Interview with former U.S. congressman Martin Dies, Sr., an attorney from Lufkin, Texas. The interview includes Dies' experiences as a Texas politician and U.S. Congressman, 1931-49 and 1950-56, and chairman of House Committee on Un-American Activities during the New Deal. Also includes his personal views on communism.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: April 23, 1966
Creator: Stephens, A. Ray & Dies, Martin
Partner: UNT Oral History Program

National Metal Casting Research Institute final report. Volume 2, Die casting research

Description: Four subprojects were completed: development and evaluation of die coatings, accelerated die life characterization of die materials, evaluation of fluid flow and solidification modeling programs, selection and characterization of Al-based die casting alloys, and influence of die materials and coatings on die casting quality.
Date: June 1, 1994
Creator: Jensen, D.
Partner: UNT Libraries Government Documents Department

Improved life of die casting dies of H13 steel by attaining improved mechanical properties and distortion control during heat treatment. Year 1 report, October 1994--September 1995

Description: Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.
Date: March 1, 1995
Creator: Wallace, J.F. & Schwam, D.
Partner: UNT Libraries Government Documents Department

Effect of composition and processing on the thermal fatigue and toughness of high performance die steels. Final report

Description: The objective of this study was to improve average die life by optimizing die steel composition and the die processing. Four different steels, K,Q,C and Premium Grade H-13 have been investigated for thermal fatigue resistance and toughness. Optimum heat treatment processing has been determined for each steel with respect to austenitizing temperature and tempering conditions. The effect of the quenching rate on the thermal fatigue resistance and toughness of the die steels and the effect of Electro-Discharge Machining (EDM) on the thermal fatigue resistance were also determined. The immersion thermal fatigue specimen developed at CWRU was used to determine the thermal fatigue resistance as characterized by the two parameters of average maximum crack length and total crack area. The Charpy V-notch impact test was used over a -100{degrees}F to 450{degrees}F testing temperature range to evaluate the toughness and the brittle-ductile transition behavior. K steel has been identified as superior in performance compared to Premium Grade H-13. Q and C provide lower toughness and thermal fatigue resistance than H-13. Faster cooling rates provide higher thermal fatigue resistance and toughness. Higher austenitizing temperatures such as 1925{degrees}F compared to 1875{degrees}F provide better thermal fatigue resistance, but lower austenitizing temperatures of 1875{degrees}F provide better toughness. Higher hardness improves thermal fatigue resistance, but reduces toughness. A minimum of Rc 46 hardness is desired for aluminum die casting dies. EDM reduces the thermal fatigue resistance compared to conventional machining operations. When the EDM process of multiple small steps of decreasing energy and post-EDM treatments are employed, the effect can be reduced to a very slight amount. Preliminary evidence of the superior performance of the K steel has been provided by ongoing field testing of inserts in multiple cavity dies.
Date: June 1, 1997
Creator: Wallace, J.F.; Wang, Y. & Schwam, D.
Partner: UNT Libraries Government Documents Department

Die Soldering in Aluminium Die Casting

Description: Two types of tests, dipping tests and dip-coating tests were carried out on small steel cylinders using pure aluminum and 380 alloy to investigate the mechanism of die soldering during aluminum die casting. Optical and scanning electron microscopy were used to study the morphology and composition of the phases formed during soldering. A soldering mechanism is postulated based on experimental observations. A soldering critical temperature is postulated at which iron begins to react with aluminum to form an aluminum-rich liquid phase and solid intermetallic compounds. When the temperature at the die surface is higher than this critical temperature, the aluminum-rich phase is liquid and joins the die with the casting during the subsequent solidification. The paper discusses the mechanism of soldering for the case of pure aluminum and 380 alloy casting in a steel mold, the factors that promote soldering, and the strength of the bond formed when soldering occurs. conditions, an aluminum-rich soldering layer may also form over the intermetallic layer. Although a significant amount of research has been conducted on the nature of these intermetallics, little is known about the conditions under which soldering occurs.
Date: March 15, 2000
Creator: Han, Q.; Kenik, E.A. & Viswanathan, S.
Partner: UNT Libraries Government Documents Department

100% foundry compatible packaging and full wafer release and die separation technique for surface micromachined devices

Description: A completely foundry compatible chip-scale package for surface micromachines has been successfully demonstrated. A pyrex (Corning 7740) glass cover is placed over the released surface micromachined die and anodically bonded to a planarized polysilicon bonding ring. Electrical feedthroughs for the surface micromachine pass underneath the polysilicon sealing ring. The package has been found to be hermetic with a leak rate of less than 5 x 10{sup {minus}8} atm cm{sup {minus}3}/s. This technology has applications in the areas of hermetic encapsulation and wafer level release and die separation.
Date: April 6, 2000
Creator: Oliver, Andrew D. & Matzke, Carolyn M.
Partner: UNT Libraries Government Documents Department

Compaction of spray-dried ceramic powders: An experimental study of the factors that control green density

Description: The pressure-compaction response of a spray-dried, 94% alumina powder containing several percent of a polymeric binder was investigated as a function of die diameter and compact aspect ratio. The results show that the die fill density decreases markedly with decreasing die diameter and aspect ratio, while the final green density (at 120 MPa) decreases only slightly under the same conditions. These results suggest that the ratio of the initial compact dimensions to the size of the granules may be much more important than previously considered.
Date: November 1, 1995
Creator: Readey, M.J. & Mahoney, F.M.
Partner: UNT Libraries Government Documents Department

A study of Franz Liszt's Totentanz: Piano and orchestra version, and piano solo version.

Description: Undoubtedly, Totentanz has been one of the most famous works by Franz Liszt. Totentanz has been recorded by many pianists and addressed in much of the vast literature about Liszt and his works; however, little research has been focused on this work. Most studies of Totentanz address only the historical background of the piece in relation to the theme based on Dies irae. Currently, there are no specific studies about the solo piano or two piano versions and only one recording was located. Liszt's own piano solo transcription of this famous work is an excellent addition to the concert repertoire. Totentanz consists of six variations that include canonic and fugato sections. The main theme is based on the Gregorian chant Dies irae, a melody that has been used by many other composers, most notably Berlioz in Witches Sabbath of Symphonie fantastique, op. 14 and Rachmaninoff in Rhapsody on a Theme of Paganini. This study contains five chapters. Chapters I and II provide background information, historical background and influences of Totentanz. Chapter III presents an outline of Liszt's achievement as a transcriber. Liszt revised his own works numerous times from the 1840s and 1850s, including Transcendental Etudes, Paganini Etudes, and piano and orchestra works. Like in the case of Totentanz, transcribed form piano and orchestra into piano solo, Liszt transcribed and paraphrased hundreds of other composers' works as well. Chapter IV discusses and compares the two main versions for solo piano and piano and orchestra. Form and harmonic language in particular the use of tritone in Totentanz is discussed. The adjustment required in transcribing the work for piano solo is discussed in detail, followed by a conclusion.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2006
Creator: Kim, Min
Partner: UNT Libraries

STUDY ON THE MECHANICAL WORKING CONDITIONS OF NUCLEAR MATERIALS AS RELATED TO ROLLING. Quarterly Report No. 2

Description: BS>Descriptions are given of: (a) the design, construction, and adjustment of a Ford plane-strain compression die, to be used in the determination of constrained yield stress curves, and (b) the design and construction of a load cell with strain gages to be used in the measurement of the rolling load during rolling. (auth)
Date: September 1, 1962
Creator: Vidal, C.A.M. & Sabato, J.A.
Partner: UNT Libraries Government Documents Department

THE FABRICATION OF HOLLOW CYLINDRICAL FUEL ELEMENTS FROM URANIUM POWDER

Description: A description is given of the die designs, dry boxes, loading cans, vacuum pots, and other experimental equipment used for fabricating hollow fuel slugs from uranium metal powder. The details of equipment operation are also given, including the die lubrication, die loading, pressing, and inspection procedures. (auth)
Date: June 1, 1954
Creator: Fugardi, J.; King, R.E. & McCullough, H.M.
Partner: UNT Libraries Government Documents Department

Crimp sealing of tubes flush with or below a fixed surface

Description: An apparatus for crimp sealing and severing tubes flush or below a fixed surface. Tube crimping below a fixed surface requires an asymmetric die and anvil configuration. The anvil must be flat so that, after crimping, it may be removed without deforming the crimped tubes. This asymmetric die and anvil is used when a ductile metal tube and valve assembly are attached to a pressure vessel which has a fixed surface around the base of the tube at the pressure vessel. A flat anvil is placed against the tube. Die guides are placed against the tube on a side opposite the anvil. A pinch-off die is inserted into the die guides against the tube. Adequate clearance for inserting the die and anvil around the tube is needed below the fixed surface. The anvil must be flat so that, after crimping, it may be removed without deforming the crimped tubes.
Date: December 1994
Creator: Fischer, Jon E.; Walmsley, Don & Wapman, P. Derek
Partner: UNT Libraries Government Documents Department

Development and Demonstration of Adanced Tooling Alloys for Molds and Dies

Description: This report summarizes research results in the project Development and Demonstration of Advanced Tooling Alloys for Molds and Dies. Molds, dies and related tooling are used to manufacture most of the plastic and metal products we use every day. Conventional fabrication of molds and dies involves a multiplicity of machining, benching and heat treatment unit operations. This approach is very expensive and time consuming. Rapid Solidifcation Process (RSP) Tooling is a spray-forming technology tailored for producing molds and dies. The appraoch combines rapid solidifcation processing and net-shape materials processing in a single step. An atomized spray of a tool-forming alloy, typically a tool steel, is deposited onto an easy-to-form tool pattern to replicate the pattern's shape and surface features. By so doing, the approach eliminates many machining operations in conventional mold making, significantly reducing cost, lead time and energy. Moreover, rapid solidification creates unique microstructural features by suppressing carbide precipitation and growth, and creating metastable phases. This can result in unique material properties following heat treatment. Spray-formed and aged tool steel dies have exhibited extended life compared to conventional dies in many forming operations such as forging, extrusion and die casting. RSP Tooling technolocy was commercialized with the formation of RSP Tooling, LLC in Solon, Oh.
Date: January 1, 2006
Creator: McHugh, Kevin M. & Lavernia, Enrique J.
Partner: UNT Libraries Government Documents Department

Simple visualization techniques for die casting part and die design. Final report, July 1, 1995--September 30, 1997

Description: The objective of this work was to develop and test die casting design evaluation techniques based on the visualization of geometric data that is related to potential defects of problems. Specifically, thickness information is used to provide insight into potential thermal problems in the part and die. Distance from the gate and a special type of animation of the fill pattern is used to provide an assessment of gate, vent and overflow locations. Techniques have been developed to convert part design information in the form of STL files to a volume-based representation called a voxel model. The use of STL files makes the process CAD system independent. Once in voxel form, methods that were developed in this work are used to identify thick regions in the part, thin regions in the part and/or die, distance from user specified entry locations (gates), and the qualitative depiction of the fill pattern. The methods were tested with a prototype implementation on the UNIX platform. The results of comparisons with numerical simulation and field reported defects were surprisingly good. The fill-related methods were also compared against short-shots and a water analog study using high speed video. The report contains the results of the testing plus detailed background material on the construction of voxel models, the methods used for displaying results, and the computational geometric reasoning methods used to create die casting-related information form the voxel model for display to the user.
Date: May 1, 1998
Creator: Miller, R.A.; Lu, S.C. & Rebello, A.B.
Partner: UNT Libraries Government Documents Department