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A summary of results of various investigations of the mechanical properties of aluminum alloys at low temperatures

Description: The available sources of data on the mechanical properties of aluminum alloys at low temperatures are listed and a summary of the material to be found in each source is given. There is included a discussion of the results of recent tests of aluminum alloys at low temperatures made at the Aluminum Research Laboratories.
Date: May 1942
Creator: Hartmann, E. C. & Sharp, W. H.
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Zirconium-Tin Alloys

Description: Abstract: "The mechanical properties and corrosion resistance of induction-melted, zirconium-tin alloys have been determined. The alloys investigated contained from zero to five per cent tin and up to 0.3% carbon. The zirconium used was United States Bureau of Mines sponge zirconium. The mechanical properties investigated include the tensile, hot-hardness, and impact properties."
Date: December 22, 1952
Creator: Schwope, A. D. & Chubb, Walston
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Iodide Zirconium Alloys

Description: Introduction: "The tensile properties, hot hardness, impact strength; and corrosion resistance of some arc-melted, iodide zirconium alloys have been determined. The alloys investigated include binary alloys of zirconium containing zero to five per cent tin, binary alloys of zirconium containing zero to 0.14 per cent nitrogen, and ternary alloys of zirconium containing tin and nitrogen, tin and uranium, and uranium and beryllium."
Date: November 1, 1952
Creator: Schwope, A. D. & Chubb, Walston
Partner: UNT Libraries Government Documents Department

The Mechanical Properties of Beta-Quenched Uranium at Elevated Temperatures

Description: The creep strength and tensile properties-were determined in vacuum for beta-quenched, derby uranium. The stresses to produce a secondary creep rate of- 0.0001 per cent per hr at 100, 250, 400, and 500 deg C were 48,000, sile strengths were 114,500, 35,100, 11,100, and 8,500 psi at temperatares of 28, 300, 500, and 700 deg C, respectively. The creep and tensile strengths decrease quite rapidly with increasing temperature in the temperatare range 250 to 400 deg C.
Date: September 6, 1955
Creator: Shober, Frederic R.; Marsh, Lyle L. & Manning, G. K.
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Zirconium and Zirconium-Uranium Alloys Containing Tin

Description: Abstract: "The mechanical properties of a large number of zirconium alloys have been investigated. These alloys include zirconium-tin and zirconium-tin-uranium. Tensile tests have been run on these alloys at room temperature, 500 F, and 600 F. Hot-hardness data have been obtained from room temperature to 1600 F, with particular emphasis on the hot-rolling range. Creep tests and fatigue tests have been run on a number of zirconium-tin alloys at 500 F."
Date: September 29, 1952
Creator: Schwope, A. D.; Muehlenkamp, G. T. & Chubb, Walston
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Zirconium and Zirconium-Uranium Alloys Containing Tin

Description: Abstract: "The mechanical properties of a large number of zirconium alloys have been investigated. These alloys include zirconium-tin and zirconium-tin-uranium. Tensile tests have been run on these alloys at room temperature, 500 F, and 600 F. Hot-hardness data have been obtained from room temperature to 1600 F, with particular emphasis on the hot-rolling range. Creep tests and fatigue tests have been run on a number of zirconium-tin alloys at 500 F."
Date: September 29, 1952
Creator: Schwope, A. D.; Muehlenkamp, G. T. & Chubb, Walston
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Zircaloy-2

Description: Abstract: The mechanical and physical properties of Zircaloy-2 were determined as a function of five test variables: temperature, grain size, direction to rolling, hydrogen content, and the presence or absence of a notch.
Date: February 1, 1961
Creator: Mehan, R. L. & Wiesinger, F. W.
Partner: UNT Libraries Government Documents Department

Investigation of alloying effects in aluminum dispersion strengthened with Al$sub 2$O$sub 3$

Description: Two types of alloying elements were investigated to determine if the room-temperature strength could be improved and if, through lowering the oxide content, the high-temperature ductility could be improved. Mg was investigated for its solid solution strengthening in one type alloy. The other type alloy involved further dispersion strengthening through adding Fe, Mo, Zr, Cr, V, and Ti which form highly stable intermetallic compounds with Al. Fabrication techniques were developed which produced uniform and reproducible rods for testing. Prealloyed powders were produced by atomizing the molten alloys and collecting the powders in water. This procedure produced uniform powders with a very fine distribution of the intermetallic compounds. Fabrication into rods then included ball-milling, vacuum hot pressing, vacuum heat treating, and hot extrusion. Mg additions improved strengths up to 200$sup 0$C with little effect above that temperature. Room-temperature tensile strengths up to 77,000 psi were obtained which are comparable to the strengths obtained in conventional aluminum alloys. The additional dispersion strengthening of the intermetallic compounds is additive to that of the oxide from room temperature to 450$sup 0$C. No significant improvements in ductility are obtained by reducing the oxide content since even at very low ball-milling times (i.e., low oxide contents) the uniform elongation at 450$sup 0$C is typically 0.5 percent. Good combinations of strength and ductility at 450$sup 0$C were obtained in some of the alloys containing intermetallic compounds with no ball-milling. Typical properties at this temperature were tensile strengths of 7,000 psi, uniform elongation of 3 percent, and total elongation of 35 percent. (21 tables, 33 fig, 43 references) (auth)
Date: October 1, 1975
Creator: Copeland, G.L.
Partner: UNT Libraries Government Documents Department

Biomimetic bonelike composites and novel bioactive glasscoatings

Description: Metallic orthopaedic implants have been successfully used for decades but they have serious shortcomings related to their osseointegration and the fact that their mechanical properties do not match those of bone. This paper reviews recent advances in the fabrication of novel coatings to improve implant osseointegration and in the development of a new generation of hybrid organic-inorganic implant materials specifically designed for orthopaedic applications.
Date: June 1, 2005
Creator: Tomsia, A.P.; Saiz, E.; Song, J. & Bertozzi, C.R.
Partner: UNT Libraries Government Documents Department

Friction Anisotropy: A unique and intrinsic property of decagonal quasicrystals

Description: We show that friction anisotropy is an intrinsic property of the atomic structure of Al-Ni-Co decagonal quasicrystals and not only of clean and well-ordered surfaces that can be prepared in vacuum [J.Y. Park et al., Science (2005)]. Friction anisotropy is manifested both in nanometer size contacts obtained with sharp atomic force microscope (AFM) tips as well as in macroscopic contacts produced in pin-on-disc tribometers. We show that the friction anisotropy, which is not observed when an amorphous oxide film covers the surface, is recovered when the film is removed due to wear. Equally important is the loss of the friction anisotropy when the quasicrystalline order is destroyed due to cumulative wear. These results reveal the intimate connection between the mechanical properties of these materials and their peculiar atomic structure.
Date: June 25, 2008
Creator: Mulleregan, Alice; Park, Jeong Young; Salmeron, Miquel; Ogetree, D.F.; Jenks, C.J.; Thiel, P.A. et al.
Partner: UNT Libraries Government Documents Department

Knowledge Discovery of Nanotube Mechanical Properties With an Informatics-Molecular Dynamics Approach

Description: Carbon nanotubes (CNT) have unparalleled mechanical properties, spanning several orders of magnitude over both length and time scales. Computational and experimental results vary greatly, partly due to the multitude of variables. Coupling physics-based molecular dynamics (MD) with informatics methodologies is proposed to navigate the large problem space. The adaptive intermolecular reactive empirical bond order (AIREBO) is used to model short range, long range and torsional interactions. A powerful approach that has not been used to study CNT mechanical properties is the derivation of descriptors and quantitative structure property relationships (QSPRs). For the study of defected single-walled CNTs (SWCNT), two descriptors were identified as critical: the density of non-sp2 hybridized carbons and the density of methyl groups functionalizing the surface. It is believed that both of these descriptors can be experimentally measured, paving the way for closed-loop computational-experimental development. Informatics can facilitate discovery of hidden knowledge. Further evaluation of the critical descriptors selected for Poisson’s ratio lead to the discovery that Poisson’s ratio has strain-varying nonlinear elastic behavior. CNT effectiveness in composites is based both on intrinsic mechanical properties and interfacial load transfer. In double-walled CNTs, inter-wall bonds are surface defects that decrease the intrinsic properties but also improve load transfer. QSPRs can be used to model these inverse effects and pinpoint the optimal amount of inter-wall bonds.
Date: May 2012
Creator: Borders, Tammie L.
Partner: UNT Libraries

Understanding and Tailoring the Mechanical Properties of LIGA Fabricated Materials

Description: LIGA fabricated materials and components exhibit several processing issues affecting their metallurgical and mechanical properties, potentially limiting their usefulness for MEMS applications. For example, LIGA processing by metal electrodeposition is very sensitive to deposition conditions which causes significant processing lot variations of mechanical and metallurgical properties. Furthermore, the process produces a material with a highly textured lenticular rnicrostructural morphology suggesting an anisotropic material response. Understanding and controlling out-of-plane anisotropy is desirable for LIGA components designed for out-of-plane flexures. Previous work by the current authors focused on results from a miniature servo-hydraulic mechanical test frame constructed for characterizing LIGA materials. Those results demonstrated microstructural and mechanical properties dependencies with plating bath current density in LIGA fabricated nickel (LIGA Ni). This presentation builds on that work and fosters a methodology for controlling the properties of LIGA fabricated materials through processing. New results include measurement of mechanical properties of LIGA fabricated copper (LIGA Cu), out-of-plane and localized mechanical property measurements using compression testing and nanoindentation of LIGA Ni and LIGA Cu.
Date: January 25, 1999
Creator: Buchheit, T.E.; Christenson, T.R.; Lavan, D.A. & Schmale, D.T.
Partner: UNT Libraries Government Documents Department

Development and Characterization of a New Epoxy Foam Encapsulant as an Ablefoam Replacement

Description: A new epoxy foam encapsulant, EF-ARIO/20, has been developed at Sandia National Laboratories (SNL) as a replacement for Ablefoam", an epoxy foam encapsulant used in the W76 Arming, Fusing, and Firing (Al%@) system. Since it contained toxic ingredients including a known carcinogen, Ablefoarn" is no longer commercially available. It has been demonstrated by scanning electron microscopy (SEM) that the microstructure of the new epoxy foam is similar to that of Ablefoam@. Mechanical properties of tensile and compressive strength, and tensile and compressive modulus, and thermal properties of glass transition temperature (.TJ, and coefficient of thermal expansion (CTE) have been measured for the new foam. Electrical properties of dielectric constant, dissipation factors, volume resistivity, and dielectric strength were also measured. These property measurements are comparable to those of Ablefoam@. Development and characterization of the new foam will be discusse~ and a comparison of mechanical, thermal, and electrical properties for the new epoxy foam and Ablefoam@ will be reported.
Date: December 1, 1998
Creator: Rand, P.B. & Russick, E.M.
Partner: UNT Libraries Government Documents Department

Thermophysical and Mechanical Properties of Polymer Liquid Crystals and Their Blends

Description: Tensile properties, namely the elastic modulus, tensile strength, percent of elongation at yield and at the break were determined for the pure components and blends. The results are connected to the respective phase diagrams and demonstrate that blending makes property manipulation possible. Blends for which the mechanical properties are better than those of pure EPs can be obtained.
Date: May 1994
Creator: López, Betty Lucy
Partner: UNT Libraries

Bonding of uranium to uranium

Description: From abstract: "Some mechanical properties of uranium joined to uranium by means of sinter welding described. The types of uranium investigated were powdered and cast material. Comparison of results obtained by the testing of the whole and joined material are presented. Although the joined material to date does not possess strength of the whole material, the results are promising. Work is continuing."
Date: 1955
Creator: Hum, Jack K. Y.
Partner: UNT Libraries Government Documents Department

An Investigation of Mechanical Properties of Honeycomb Structures Made of Resin-Impregnated Paper

Description: Note presenting an investigation to determine the order of magnitude of the important mechanical properties of honeycomb-like structures. Some of the characteristics improved by the structure include the rigidity, shear stress at proportional limit, and shear strength as compared to balsa wood. Some of the negative characteristics include the modulus of electricity, compressive stress at proportional limit, compressive strength, and tensile strength.
Date: May 1948
Creator: Norris, C. B. & Mackin, G. E.
Partner: UNT Libraries Government Documents Department

Investigation of the effects of intense pulsed particle beams on the durability of metal-to-plastic interfaces.

Description: We have investigated the potential for intense particle beam surface modification to improve the mechanical properties of materials commonly used in the human body for contact surfaces in, for example, hip and knee implants. The materials studied include Ultra-High Molecular Weight Polyethylene (UHMWPE), Ti-6Al-4Al (titanium alloy), and Co-Cr-Mo alloy. Samples in flat form were exposed to both ion and electron beams (UHMWPE), and to ion beam treatment (metals). Post-analysis indicated a degradation in bulk properties of the UHMWPE, except in the case of the lightest ion fluence tested. A surface-alloyed Hf/Ti layer on the Ti-6Al-4V is found to improve surface wear durability, and have favorable biocompatibility. A promising nanolaminate ceramic coating is applied to the Co-Cr-Mo to improve surface hardness.
Date: February 1, 2005
Creator: Prasad, Somuri V.; Renk, Timothy J.; Provencio, Paula Polyak; Petersen, Donald W. (University of Alabama, Birmingham, AL); Petersen, Thomas D. (University of California, San Diego, CA); Buchheit, Thomas Edward et al.
Partner: UNT Libraries Government Documents Department

Influence of design and coatings on the mechanical reliability of semiconductor wafers.

Description: We investigate some of the mechanical design factors of wafers and the effect on strength. Thin, solid, pre-stressed films are proposed as a means to improve the bulk mechanical properties of a wafer. Three-point bending was used to evaluate the laser scribe density and chemical processing effect on wafer strength. Drop and strike tests were employed to investigate the edge bevel profile effect on the mechanical properties of the wafer. To characterize the effect of thin films on strength, one-micron ceramic films were deposited on wafers using PECVD. Coated samples were prepared by cleaving and were tested using four-point bending. Film adhesion was characterized by notched four-point bending. RBS and FTIR were used to obtain film chemistry, and nanoindentation was used to investigate thin film mechanical properties. A stress measurement gauge characterized residual film stress. Mechanical properties of the wafers correlated to the residual stress in the film.
Date: August 2002
Creator: Yoder, Karl J.
Partner: UNT Libraries

The Properties and Heat Treatment of Zirconium-Uranium Alloys

Description: From Abstract: "The heat treatment and mechanical properties of four zirconium alloys...were investigated. Tensile, hardness, Jominy end-quench, and metallographic data constitute the basis for much of the report. Other data reported include the results of high-temperature creep, tensile, hardness, cold rolling, thermal-cycling, and dynamic-modulus tests." A connection is made between the behavior of these four alloys and more alloys in the zirconium-uranium system.
Date: January 10, 1955
Creator: Chubb, Walston; Muehlenkamp, G. T. & Manning, G. K.
Partner: UNT Libraries Government Documents Department