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The Corrosion of Magnesium and of the Magnesium Aluminum Alloys Containing Manganese

Description: "The extensive use of magnesium and its alloys in aircraft has been seriously handicapped by the uncertainties surrounding their resistance to corrosion. This problem has been given intense study by the American Magnesium Corporation and at the request of the Subcommittee on Materials for Aircraft of the National Advisory Committee for Aeronautics this report was prepared on the corrosion of magnesium" (p. 419).
Date: 1927
Creator: Boyer, J. A.
Partner: UNT Libraries Government Documents Department

Interfacial structures and energetics of the strengthening precipitate phase in creep-resistant Mg-Nd-based alloys

Description: This article discusses the study of two interfaces– {112}β1/{1100}Mg and {111}β1/{1120}Mg– that are commensurate with β1/hcp-Mg orientation relationship via first principles calculations.
Date: January 17, 2017
Creator: Choudhuri, Deep; Banerjee, Rajarshi & Srivilliputhur, Srinivasan
Partner: UNT College of Engineering

Bearing tests of magnesium-alloy sheet

Description: From Summary: "Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given."
Date: June 1943
Creator: Sharp, W. H. & Moore, R. L.
Partner: UNT Libraries Government Documents Department

Bearing strength of some sand-cast magnesium alloys

Description: Report presenting testing to determine the bearing strength characteristics of some magnesium-alloy sand castings and the relation between those and more commonly determined tensile properties. The primary sand-cast magnesium alloys of interest for aircraft design are AM403, AM260, and AM265. Results of all of the tension, compression, and shear tests are provided in tables.
Date: February 1947
Creator: Moore, R. L.
Partner: UNT Libraries Government Documents Department

The Determination of Hydrogen in Magnesium, Lithium, and Magnesium Alloys

Description: The following report describes the process of the determination of hydrogen in magnesium, lithium, and magnesium alloys, including methods of analyzing magnesium-lithium alloys for hydrogen, and the tin-fusion method used for determining the hydrogen content of pure magnesium that can also be used to analyze pure lithium for hydrogen.
Date: November 13, 1951
Creator: Mallett, Manley William, 1909-; Gerds, A. F. & Griffith, C. B.
Partner: UNT Libraries Government Documents Department

Plate compressive strength of FS-1H magnesium-alloy sheet and a maximum-strength formula for magnesium-alloy and aluminum-alloy formed sections

Description: From Summary: "The plate compressive strength of FS-1h magnesium-alloy sheet was determined from local-instability tests of formed Z-section columns. The critical compressive stress was found to correlate well with the compressive stress-strain curve for the material. The curves of average stress at maximum load plotted against calculated elastic critical strain resulted in a family of curves similar to previous results for aluminum-alloy sheet."
Date: October 1948
Creator: Gallaher, George L.
Partner: UNT Libraries Government Documents Department

Magnesium-Uranium Alloy System

Description: Analytical, x-ray, thermal, and metallographic data have been obtained in the study of the magnesium-uranium system, and a proposed phase diagram has been constructed.
Date: 1954
Creator: Tracy, George A.; Chiotti, P. & Wilhelm, Harley A.
Partner: UNT Libraries Government Documents Department

Microstructure for Enhanced Plasticity and Toughness

Description: Magnesium is the lightest metal with a very high specific strength. However, its practical applicability is limited by its toughness and reliability. Mg, being HCP has low ductility. This makes the improvement of toughness a grand challenge in Mg alloys. Friction stir processing (FSP) is a thermomechanical technique used to effect microstructural modification. Here, FSP was utilized to affect the toughness of WE43 sheets through microstructural modification. Room temperature Kahn-type tests were conducted to measure the toughness of WE43 sheets. Microscopic techniques (SEM, TEM) was utilized to study the effect of various microstructural factors like grain size, texture, constituent particles, precipitates on crack initiation and propagation. Tensile properties were evaluated by mini-tensile tests. Crack growth in WE43 sheets was also affected by mechanics and digital image correlation (DIC) was utilized to study the plastic zone size. The underlying mechanisms affecting toughness of these sheets were understood which will help in formulating ways in improving it. WE43 nanocomposites were fabricated via FSP. Uniform distribution of reinforcements was obtained in the composites. Improved mechanical properties like that of enhanced strength, increased hardness and stiffness were obtained. But contrary to other metal matrix composites which show reduction in ductility with incorporation of ceramic reinforcements, the nanocomposites showed good strength-ductility combination. The composites were precisely characterized and mechanisms governing this property were studied. The nano-length of the reinforcements was observed to be the main criteria and the dislocation-particle interaction, the main reason behind the strength-ductility property.
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Date: August 2016
Creator: Das, Shamiparna
Partner: UNT Libraries

Effect of Open Circular Holes on Tensile Strength and Elongation of Sheet Specimens of a Magnesium Alloy

Description: Note presenting an investigation of the effect of open circular holes on the tensile strength and elongation of sheet specimens of magnesium alloy AM-C52S in both the annealed and hard-rolled condition. Tests were made to study the effect of variable ratio of hole diameter to total specimen width and the effect of spacing and arrangement of the holes.
Date: June 1952
Creator: Barker, R. S.
Partner: UNT Libraries Government Documents Department

PROPERTIES AND HANDLING PRACTICES FOR MAGNESIUM: A LITERATURE SURVEY

Description: A survey of Mg including the cost and availability of various high- purity grades, safe handling considerations, methods of distillation and production physical and thermodynamic properties, and the binary and ternary alloys is presented. A bibliography is included with 157 references. (J.R.D.)
Date: March 1, 1958
Creator: Breederman, M.; Bennett, G.A.; Burris, L. Jr.; Dillon, I.G.; Winsch, I.O.; Nathans, M.W. et al.
Partner: UNT Libraries Government Documents Department

Interfacial segregation and deformation of superplastically deformed Al-Mg-Mn alloys

Description: Microstructural and microchemical studies have been carried out on superplastically deformed Al-Mg-Mn (AA5083-type) alloys. Grain boundary composition was measured using a Scanning Auger Microprobe (SAM) and an Analytical Transmission Electron Microscope (ATEM), while conventional TEM was used for microstructural evaluation. Non-equilibrium segregation of Si to grain boundaries following deformation was measured by both techniques. Significant interfacial Si enrichment was only detected in gage sections of tensile specimens after uniaxial strains from 50 to 200%. Grip regions which experience identical thermal histories, but without plastic deformation, did not reveal Si segregation. Selected samples also showed a slight depletion of Mg at grain boundaries after deformation. The only reproducible observation of equilibrium segregation was in Zr-modified alloys, where Sn was detected by SAM in both the deformed and undeformed sections of the sample. Microstructural analysis documented subgrain formation and subgrain-precipitate interactions during superplastic deformation. In addition, many grain boundaries and precipitate interfaces contained small (5 to 20 nm) voids. Compositional analysis of these nano-voids revealed that they were enriched in Mg with the adjacent boundary regions correspondingly depleted.
Date: March 1, 1995
Creator: Vetrano, J.S.; Lavender, C.A. & Bruemmer, S.M.
Partner: UNT Libraries Government Documents Department

Ceramic materials testing and modeling

Description: Certain refractory ceramics (notably oxides) have desirable properties suitable for the construction of ceramic waste containers for long term use in nuclear waste disposal applications. In particular, they are far less prone to environmental corrosion than metals under realistic repository conditions. The aqueous corrosion rates of oxides such as magnesium aluminate spinel (MgAl{sub 2}0{sub 4}) and alumina (Al{sub 2}0{sub 4}) fall in the range of a few millimeters per million years. Oxide ceramics are also not likely to be subject to microbiologically influenced corrosion, which apparently can attack most, if not all, of the available engineering metals. Ceramics have a reputation for poor mechanical performance and large, impermeable objects are not easily fabricated by most current fabrication methods. As a result, the most promising approach for incorporating ceramics in large waste packages appears to be to apply a high density ceramic coating to a supporting metallic structure. Ceramic coatings 2048 applied by a thermal spray technique can be made effectively seamless and provide a method for final closure of the waste package while maintaining low average temperatures for the entire assembly. The corrosion resistance of the ceramic should prevent or delay water penetration to the underlying metal, which will in turn provide most of the mechanical strength and toughness required by the application. In this way, the major concerns regarding the ceramic coating become ensuring it is impervious to moisture, its adherence and its resistance to mechanical stresses during handling or resulting from rock fall in the repository. Without water, electrochemical corrosion and microbiologically influenced corrosion processes are considered impossible, so a complete coating should protect the metal vessels for far longer than the current design requirements. Even an imperfect coating should extend the life of the package, delaying the onset and reducing the severity of corrosion by limiting the ...
Date: April 30, 1998
Creator: Wilfinger, K. R., LLNL
Partner: UNT Libraries Government Documents Department

Laser beam welding of AZ31B-H24 magnesium alloy.

Description: The laser beam weldability of AZ31B magnesium alloy was examined with high power CW CO{sub 2} and pulsed Nd:YAG lasers. The low viscosity and surface tension of the melt pool make magnesium more difficult to weld than steel. Welding parameters necessary to obtain good welds were determined for both CW CO{sub 2} and pulsed Nd:YAG lasers. The weldability of the magnesium alloy was significantly better with the Nd:YAG laser. The cause of this improvement was attributed to the higher absorption of the Nd:YAG beam. A lower threshold beam irradiance was required for welding, and a more stable weldpool was obtained.
Date: September 29, 1998
Creator: Leong, K. H.
Partner: UNT Libraries Government Documents Department

Enhanced tensile ductility in Al-Mg alloys by solid-solution interactions

Description: The development of methods for obtaining high tensile elongation in aluminum alloys is of great importance for the practical forming of near-net-shape parts. Current superplastic alloys are limited in use by high material costs. The utilization of solute-drag creep processes, the approach used in this study, to obtain enhanced tensile ductility in aluminum alloys has lead to tensile elongations of up to 325% in simple, binary Al-Mg alloys with coarse grain sizes. This method has the advantage of lowering processing costs in comparison with superplastic alloys because a fine grain size is not necessary. Whereas superplastic alloys typically have a strain-rate sensitivity of m = 0.5, the enhanced ductility Al-Mg alloys typically exhibit m = 0.3 where maximum ductility is observed. Although a strain-rate sensitivity of rn = 0.5 can lead to elongations of over 1000% (superplastic materials) a value of m = 0.3 is shown experimentally to be sufficient for obtaining elongations of 150% to a maximum observed of 325%. Enhanced ductility is also affected strongly by ternary alloying additions, such as Mn, for which a preliminary understanding is pursued.
Date: November 29, 1995
Creator: Taleff, E.M.; Henshall, G.A.; Lesuer, D.R.; Nieh, T.G. & Wadsworth, J.
Partner: UNT Libraries Government Documents Department

Energy and Technolgy Assessment of Zinc and Magnesium Casting Plants, Technical Report Close-out, August 25,2006

Description: Twin City Die Castings Company of Minneapolis, Minnesota, Twin City Die Castings Company was awarded project No. DE-FG36-05GO15097 to perform plant wide assessments of ten (10) die casting facilities that produce zinc and magnesium alloy castings in order to determine improvements and potential cost savings in energy use. Mr. Heider filled the role of team leader for the project and utilized the North American Die Casting Association (NADCA) to conduct audits at team participant plants so as to hold findings specific to each plant proprietary. The intended benefits of the project were to improve energy use through higher operational and process efficiency for the plants assessed. An improvement in energy efficiency of 5 – 15% was targeted. The primary objectives of the project was to: 1) Expand an energy and technology tool developed by the NADCA under a previous DOE project titled, “Energy and Technology Assessment for Die Casting Plants” for assessing aluminum die casting plants to be more specifically applicable to zinc and magnesium die casting facilities. 2) Conduct ten (10) assessments of zinc and magnesium die casting plants, within eight (8) companies, utilizing the assessment tool to identify, evaluate and recommend opportunities to enhance energy efficiency, minimize waste, and improve productivity. 3) Transfer the assessment tool to the die casting industry at large.
Date: August 25, 2006
Creator: Twin City Die Castings Company
Partner: UNT Libraries Government Documents Department

PRETREATMENT OF FUEL ELEMENTS. Technical Report No. 48 Chapter 130

Description: A revitew is presented of pretreatment methods with special attention to those useful at Eurochemic. Mechanical and chemitcal decanning methods presently in use or proposed for Al-, Mg-, stainiless steel-, and Zror Zr alloy-jacketed fuels are discussed. Darex, Sulfex, and Zirflex processes are included along with special methods ror U-- Mo and U- Zr fuels. (T.R.H.)
Date: January 1, 1958
Creator: Detilleux, E
Partner: UNT Libraries Government Documents Department

Strength and flexibility of bulk high-{Tc} superconductors

Description: Strength, fracture toughness, and elastic modulus data have been gathered for bulk high-temperature superconductors, commercial 99.9% Ag, and a 1.2 at.% Mg/Ag alloy. These data have been used to calculate fracture strains for bulk conductors. The calculations indicate that the superconducting cores of clad tapes should begin to fracture at strains below 0.2%. In addition, residual strains in Ag-clad (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes have been measured by neutron diffraction. An explanation is offered for why many tapes appear to be able to tolerate large strains before exhibiting a reduction in current transport.
Date: August 1, 1996
Creator: Goretta, K.C.; Jiang, M.; Kupperman, D.S.; Lanagan, M.T.; Singh, J.P.; Vasanthamohan, N. et al.
Partner: UNT Libraries Government Documents Department

Laminated metal composite formed from low flow stress layers and high flow stress layers using flow constraining elements and method of making same

Description: This invention relates to a laminated metal composite, comprising alternating layers of low flow stress material and high flow stress material, and formed using flow constraining elements around each low flow stress layer; and a method of making same. A composite is a combination of at least two chemically distinct materials with a distinct interface separating the two materials. A metal matrix composite (MMC) is a composite material composed of a metal and a nonmetallic reinforcing agent such as silicon carbide (SiC) or graphite in continuous or discontinuous fiber, whisker, or discrete particulate form. A laminate is a material composed of several bonded layers. It is possible to have a laminate composed of multi-layers of a single type of material bonded to each other. However, such a laminate would not be considered to be a composite. The term {open_quotes}laminated metal composite{close_quotes} (LMC), as used herein, is intended to include a structural material composed of: (1) layers of metal or metal alloys interleaved with (2) a different metal, a metal alloy, or a metal matrix composite (MMC) containing strengthening agents.
Date: December 31, 1994
Creator: Syn, C.K. & Lesuer, D.R.
Partner: UNT Libraries Government Documents Department

Microstructure-strength relationships of heavily deformed magnesium-lithium composites containing steel fibers

Description: The successful development of deformation-processed metal-metal composites (DMMC) offers the potential for ductile, high-strength structural materials with high-temperature stability. An infiltration casting process was used to permeate steel wool preforms with molten magnesium-lithium (Mg-Li) alloys. The selected matrix alloys were hexagonal close packed (HCP) Mg-4wt%Li or body centered cubic (BCC) Mg-12wt%Li; the low carbon steel wool fibers were predominantly BCC ferrite. These cast HCP/BCC and BCC/BCC composites were deformed by rolling or by extrusion and swaging. Mechanical properties, microstructure, and texture development of the composites were characterized at various levels of deformation. The HCP/BCC composites had limited formability at temperatures up to 400 C while the BCC/BCC composites had excellent formability during sheet rolling at room temperature but limited formability during swaging at room temperature. The tensile strengths of these HCP/BCC and BCC/BCC composite materials increased moderately with deformation, though less than predicted from rule of mixtures (ROM) calculations. The microstructure was characterized to correlate the filament size to the deformation strain and mechanical properties of the composite material. Stereological measurements of the filament size were used to adjust ROM calculations to reflect the actual deformation strain in the fibers. However, the experimental strengths of these composite materials were still less than ROM predictions, possibly due to the presence of considerably large fibers. Of the many models used to describe the strengthening observed in DMMC materials, the Hall-Petch relationship adequately described the experimental data. Texture development was also characterized to explain the deformation characteristics of the composite materials. Chapters 2, 3 and 4 are not included here. They are being processed separately.
Date: October 8, 1997
Creator: Jensen, J.
Partner: UNT Libraries Government Documents Department

Storage of hydrogen in powders with nanosized crystalline domains

Description: The term nanostructured materials is being used in the literature to denote different materials prepared by different techniques: (a) by the gas condensation of vapors in a partial vacuum and (b) by mechanical alloying, a high energy ball milling technique. The authors discuss the origin of this confusion and propose a differentiating nomenclature. They then discuss the use of particles with nanosized structures for the storage of hydrogen.
Date: September 1997
Creator: Schwarz, R. B.
Partner: UNT Libraries Government Documents Department

3-D Measurement of Deformation Microstructure of Al(0.2%)Mg Using Submicron Resolution White X-Ray Microbeams

Description: We have used submicron-resolution white x-ray microbeams on the MHATT-CAT beamline 7-ID at the Advanced Photon Source to develop techniques for three-dimensional investigation of the deformation microstructure in a 20% plane strain compressed Al(0.2%)Mg tri-crystal. Kirkpatrick-Baez mirrors were used to focus white radiation from an undulator to a 0.7 x 0.7 {micro}m{sup 2} beam that was scanned over bi- and tri-crystal regions near the triple-junction of the tri-crystal. Depth resolution along the x-ray microbeam of less than 5 microns was achieved by triangulation to the diffractibn source point using images taken at a series of CCD distances from the microbeam. Computer indexing of the deformation cell structure in the bi-crystal region provided orientations of individual subgrains to {approximately}0.01 degrees, making possible detailed measurements of the rotation axes between individual cells.
Date: November 29, 1999
Creator: Larson, B. C.; tamura, N.; Chung, J.-S.; Ice, G. E.; Budai, J. D.; Tischler, J. Z. et al.
Partner: UNT Libraries Government Documents Department

Potential applications of wrought magnesium alloys for passenger vehicles

Description: Vehicle weight reduction is one of the major means available for improving automotive fuel efficiency. Although high-strength steels, aluminum (Al), and polymers are already being used to achieve significant weight reductions, substantial additional weight reductions could be achieved by increased use of magnesium (Mg) and its alloys, which have very low density. Magnesium alloys are currently used in relatively small quantities for auto parts; use is generally limited to die castings, such as housings. The Center for Transportation Research at Argonne National Laboratory has performed a study for the Lightweight Materials Program within DOE`s Office of Transportation Materials to evaluate the suitability of wrought Mg and its alloys to replace steel or aluminum for automotive structural and sheet applications. This study identifies technical and economic barriers to this replacement and suggests R&D areas to enable economical large-volume use. Detailed results of the study will be published at a later date. Magnesium sheet could be used in body nonstructural and semi-structural applications, while extrusions could be used in such structural applications as spaceframes. Currently, Mg sheet has found limited use in the aerospace industry, where costs are not a major concern. The major barrier to greatly increased automotive use is high cost; two technical R&D areas are identified that could enable major reductions in costs. These are novel reduction technology and better hot-forming technology, possibly operating at lower temperatures and involving superplastic behavior.
Date: December 31, 1995
Creator: Gaines, L.; Cuenca, R.; Stodolsky, F. & Wu, S.
Partner: UNT Libraries Government Documents Department