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Designers of transportation vehicles (air, land, or sea) continually seek ways to reduce vehicle weight in response to increasing fuel economy mandates, mission requirements, or other competitive pressures. One way to do this is by the selection of material types and their properties based on functional and structural requirements. While these material changes can help meet performance mandates, their implementation in a production environment relies on retaining economic competitiveness. This article traces the history of the various joining processes relevant to the current challenge in joining the very dissimilar families of steel (Fe) and aluminum (Al) alloys. [ABSTRACT FROM AUTHOR]

There is detailed literature on the mobilization of aluminum (Al) from soil to surface waters as a result of elevated acidic deposition to base-poor forest watersheds. There is considerably less information on the mobilization and effects of Al from the application of alum that is used in some water supplies to control turbidity during high-flow events. We report on the results of field measurements, laboratory sediment release experiments, and chemical equilibrium calculations conducted to evaluate the potential for the mobilization of Al from alum floc deposits in sediments of Kensico Reservoir, New York. Under ambient water quality conditions, mobilization of sediment Al is not a noteworthy concern at Kensico Reservoir. However, under experimental conditions of low pH, low acid neutralizing capacity (ANC), and low temperature, the inorganic fraction of monomeric Al can be mobilized from Kensico sediments to concentrations that would likely impair the health of aquatic organisms (>2 μmol/l). Elevated concentrations of monomeric Al were observed only when ANC decreased below 50 μeq/l, which is outside the range of values observed in Kensico during the 1997-2007 interval (120-460 μeq/l). Concentrations of complexing ligands are relatively low in Kensico waters (i.e., fluoride, naturally occurring organic solutes) and do not appear to substantially contribute to potential Al mobilization. For other water supplies with low ANC, the potential for sediment release of Al may exist. [ABSTRACT FROM AUTHOR]

Considerable effort is being devoted to development and regulatory qualification of low enriched fuels for research and test reactors by many agencies worldwide. One promising fuel configuration being examined for United States higher power research and test reactors (USHPRRs) are plate-type fuels composed of a metallic uranium-molybdenum foil clad in an aluminum alloy. The two pieces of aluminum alloy cladding are bonded using a hot isostatic pressing method. The mechanical properties of the resulting bond line in the aluminum alloy cladding will vary by the HIP'ing parameters, requiring a need to characterize the bond line. Small scale mechanical testing can provide a path for evaluating the mechanical properties and deformation behavior of the bond line both prior to and following irradiation. In this research, room temperature micro-tensile specimens of non-irradiated and irradiated samples containing an Al alloy (AA 6061) bond line were tested to evaluate its strength and deformation behavior. Observations indicated that the strain rate did not affect the deformation behavior or strength and most of the micro-tensile specimens failed in a ductile mode in grains around the bond line. There was no indication that the microstructural features from the bond line affected the mechanical properties of the micro-tensile specimens. An initial examination was performed on irradiated material but further systematic studies of the effects of irradiation can be performed in the future. [ABSTRACT FROM AUTHOR]

During the twentieth century, aluminium became an essential metal in the aircraft industry. Beginning with the cylinder block of the engine that powered the Wright brother's plane at Kitty Hawk in 1903, which was a one-piece casting in an aluminium alloy containing 8% copper, the use of aluminium has grown. In this article, because some reference to US military specifications and industry association guides is made, both US and equivalent metric units will be used together. In 1907 aluminium was used in propeller blades. In 1908 aluminium parts were used in control mechanisms of aircraft. Aluminium covers, seats, cowlings, cast brackets and similar parts were common by the beginning of the the First World War. In 1916, a reconnaissance bomber was developed that used aluminium in the working structure of the airplane for the first time. [ABSTRACT FROM AUTHOR]

The impacts of some high-pressure diecasting (HPDC) process parameters on greenhouse gas (GHG) emissions are quantified using life cycle analysis (LCA) for both aluminum and magnesium alloys. The study was conducted according to ISO 14040 standards and was based on an automotive component made on cold-chamber HPDC machines operating in typical mass production environments. The aluminum alloy foundry was located in Australia; the magnesium alloy foundry was located in the United States. In both cases, emissions were found to reduce with an increasing HPDC process yield. However, yield variations had only a modest impact on GHG emissions in the aluminum alloy HPDC, due to the excellent in-plant recycling of the alloy and the relatively low emissions from primary aluminum production compared with primary magnesium production. In contrast, for the magnesium alloy, significant reductions in emissions were recorded as the yield increased. This outcome was attributed to the considerable savings achieved in raw material quantities sourced from high-emitting primary production and the use of lower amounts of SF6, a GHG with a very high global warming potential (GWP). These results were found to hold irrespective of changes to the ratio between the primary and secondary alloys in the raw material mix, although the magnitude of the impact was reduced considerably with reductions in the primary alloy component. In the case of the magnesium alloy HPDC, decreases in quality assurance (QA) rejects and cycle times were also found to contribute toward reduced emissions, although their influences were an order of magnitude lower than that of the yield improvements. [ABSTRACT FROM AUTHOR]

The present paper is a summary of the R&D results obtained through SSC SR-1446 project sponsored by Ship Structure Committee together with Alcan Marine, France, and Lloyd's Register Educational Trust, UK. It is recognized that the use of ultimate limit state (ULS) design method in addition to more conventional structural design standards will help make possible to move high-speed vessels to open-ocean transiting of large high-speed vessels, which is what the US Navy is certainly trying to do. The aim of the project is to investigate the collapse characteristics of aluminum stiffened plate structures used for marine applications by mechanical testing, together with nonlinear finite element analysis (FEA). Fabrication-related initial imperfections significantly affect the ULS behavior, and thus it is of vital importance to identify the features of initial imperfections prior to ULS computations. In the present study, a statistical database of fabrication- related initial imperfectionson welded aluminum stiffened plate structures is also developed. The database and insights developed will be useful for design and building of welded aluminum high-speed oceangoing vessel structures. [ABSTRACT FROM AUTHOR]

Abstract: This paper summarizes two new satellite impact experiments. The objective of the experiments was to investigate the outcome of low- and hyper-velocity impacts on two identical target satellites. The first experiment was performed at a low-velocity of 1.5km/s using a 40-g aluminum alloy sphere. The second experiment was performed at a hyper-velocity of 4.4km/s using a 4-g aluminum alloy sphere. The target satellites were 15cm×15cm×15cm in size and 800g in mass. The ratios of impact energy to target mass for the two experiments were approximately the same. The target satellites were completely fragmented in both experiments, although there were some differences in the characteristics of the fragments. The projectile of the low-velocity impact experiment was partially fragmented while the projectile of the hyper-velocity impact experiment was completely fragmented beyond recognition. To date, approximately 1500 fragments from each impact experiment have been collected for detailed analysis. Each piece has been weighed, measured, and analyzed based on the analytic method used in the NASA Standard Breakup Model (2000 revision). These fragments account for about 95% of the target mass for both impact experiments. Preliminary analysis results will be presented in this paper. [Copyright &y& Elsevier]

The use of aluminum alloys in automobile production is growing as automakers strive to lower vehicle fuel consumption and reduce emissions by substituting aluminum for steel. The current recycling infrastructure for end-of-life vehicles is mature, profitable, and well suited to steel-intensive vehicles; increased use of cast and wrought aluminum, however, will present new challenges and opportunities to the disassembler and shredder, who now comprise the first stages of the vehicle recycling infrastructure. Using goal programming techniques, a model of the auto recycling infrastructure is used to assess the materials streams and process profitabilities for several different aluminum-intensive vehicle (AIV) processing scenarios. The first case simulates the processing of an AIV in the current recycling infrastructure. Various changes to the initial case demonstrate the consequences to the disassembler and shredder profitabilities whenever the price of nonferrous metals changes; greater fractions of the vehicle are removed as parts; the parts removed by the disassembler have increased aluminum content; the quantity of polymer removed by the disassembler is increased; the disassembly costs increase; the disposal costs for shredder residue and hazardous materials increase; the shredder processing costs increase; and different AIV designs are considered. These profits are also compared to those achieved for a steel unibody vehicle to highlight the impact of introducing AIVs into the existing infrastructure. Results indicate that the existing infrastructure will be able to accommodate AIVs without economic detriment. [ABSTRACT FROM AUTHOR]

The United States government currently manages nearly 13 metric tons of aluminum-clad spent nuclear fuel (SNF) without a long-term storage solution, so a fundamental understanding of corrosion processes occurring on aluminum alloy surfaces is of utmost importance to plan for extended (>50 years) interim dry storage of aluminum-clad SNF. While thermal and chemical corrosion processes are well characterized for aluminum, radiation effects are not. To help understand the impacts of radiation on aluminum-clad SNF, the radiation-induced molecular hydrogen gas (H 2) generation from pristine and pre-corroded aluminum alloy 1100 (Al-1100) coupons has been studied. Corrosion of coupons was achieved by submerging coupons in water at 95 °C for 29 days, yielding a ~5 μm boehmite/bayerite oxide film. Pre-corroded coupons were exposed to cobalt-60 gamma radiation to absorbed doses of up to 1.0 MGy under a variety of conditions: cover-gas composition (argon, nitrogen, or air), relative humidity (0, 50, and 100%), and temperature (ambient, 100, and 200 °C). Post-irradiation measurements demonstrated that the yield of H 2 was directly attributable to the presence of the Al-1100 coupons and their physisorbed water with dependence on absorbed gamma dose, relative humidity, and cover-gas composition. No H 2 was quantified in the presence of air, while both nitrogen and argon environments afforded higher H 2 yields with increasing relative humidities. This was attributed to the greater availability of adsorbed water for radiolytic processes. Irradiation of pre-corroded Al-1100 coupons at different temperatures under 0% relative humidity argon conditions yielded statistically equivalent H 2 yields for ambient temperatures and 100 °C. However, irradiation at 200 °C promoted a 3 to 4-fold increase in the yield of H 2 , possibly due to the transformation of bayerite to boehmite and/or improved efficiency of H• and H 2 release from oxide surfaces. • Pristine and pre-corroded Al-1100 coupons were exposed to gamma radiation in argon, nitrogen, and air gaseous environments. • Absorption of γ-radiation energy by the Al-1100 coupons generated H 2 but did not significantly alter the aluminum surface. • The presence of oxyhydroxide corrosion deposits promoted H 2 generation, relative to the assumed alumina on pristine coupons. • The H 2 generation rate followed argon > nitrogen > air coupon environments. [ABSTRACT FROM AUTHOR]

The article offers information on the research projects funded by the American Foundry Society Inc. (AFS). It notes that the project standard test for machinability of cast iron aims to develop a standard machinability comparative test to compare material of the same grade. It further states the project optimizing mechanical properties of cast aluminum alloys is intended to establish a data base with properties of cast aluminum alloys.

The article presents several research projects funded and monitored by the American Foundry Society Inc. in the U.S. Topics of the research include the standard test for machinability of cast iron, mechanical properties of cast aluminum alloys and skin on the tensile properties of iron castings. It also presents research on how to achieve lightweight casting solutions for defense applications and the effects of varying liquid iron purity on cast iron performance.

The article presents several research funded and monitored by the American Metalcasting Consortium, U.S. Department of Defense and Defense Logistic Agency. Topics of the researches include the E-357 aluminum statistical properties, casting standards and specifications and acquiring superior weapons thru casting. It also presents research on the properties of cast aluminum alloy, the use of foam patterns to strenghten metal castings and visual inspection of cast products.