1–10 of about 13700 matches for aluminum OR al
Thermodynamic Modeling and Experimental Investigation of the Magnesium-Aluminum-Strontium-Calcium System (20082840)
Proceedings of the Third International Conference on Light Metals Technology Sept 24-26 2007 Quebec, Canada P53-57
The phase equilibria and thermodynamic properties of the Mg-Al-Sr-Ca system were analyzed in this work and a thermodynamic description of the system was obtained using a computerized optimization procedure. The available thermodynamic and phase diagram data were critically assessed for all the binary and ternary sub-systems. Optimized thermodynamic properties of the binary systems were then used to construct a database and calculate the ternary phase diagrams. The phase equilibria in the Mg-Al-Sr and Mg-Al-Ca systems were investigated experimentally by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and quantitative electron probe micro-analysis (EPMA). A new ternary solid solution, MgxAl4xSr, was observed in the Mg-Al-Sr system, which is due to the substitution of Al by Mg atoms in the Al4Sr compound. Maximum solubilities of 21.3 at.% Al in Mg17Sr2 and 11.4 at.% Al in Mg were observed. It was also noticed that Mg38Sr9 dissolved 12.5 at.% Al, In the Mg-Al-Ca ternary system, one of the invariant transformation, predicted by thermodynamic modeling, was verified experimentally and found to occur at 512°C with composition close to 10.8 at.% Ca, 79.5 at.% Mg ad 9.7 at.% Al. Large solid solubility of Al in Mg2Ca was observed. The Mg-Ca-Sr and Al-Ca-Sr phase diagrams were also calculated from the established database for the Mg-Al-Ca-Sr system.
Development of Alcoa Aluminum Foam Products (20082874)
Proceedings of the Third International Conference on Light Metals Technology Sept 24-26 2007 Quebec, Canada P217-222
Aluminum foams have achieved only a fraction of market acceptance enjoyed by polymeric foams, even though aluminum foams offer the potential of superior service performance and improved environmental sustainability. This presentation describes a new light weight aluminum foam product developed at Alcoa Technical Center to capture this potential. Through the controlled decomposition of carbonate powders within molten aluminum, a stable, foamable suspension is created that resists both coalescence and drainage. A novel processing method provides for the economical production of wide panels of self-stabilized aluminum foam. The physical and mechanical properties of these fined celled aluminum foams are related to their cellular structure and the properties of these fined celled aluminum foams are related to their cellular structure and the properties of the aluminum alloy matrix from attractive combination of performance attributes, such as low density, high rigidity, high energy absorption and fire resistance, and contributes to Alcoa’s sustainability goals of energy efficiency and recycling through high aluminum scrap tolerance. A range of product applications incorporating Alcoa Aluminum Foam, n both monolithic form as well as a core material in laminate structure, is currently being studied for service in the building, construction and transportation markets. Performance of Alcoa Aluminum Foam products under different service conditions will be discussed.
Experimental Observations of Dendrite Coarsening & Al-Si Eutectic Growth in Progressively Quenched Structures of Al-Si-Cu Casting Alloys (20082951)
International Journal of Metalcasting V2 I2 P57-75
Computer controlled thermal heating and cooling curve cycles of the W319 (Al-7.5Si-3.5Cu-0.3Fe) and the WA328 (Al-9Si-1Cu-0.3Fe) alloy samples were studied in this work. Both alloys contain residual levels of Sr (~20 ppm max) and are processed with no grain refiner. From the cooling curve portion of the thermal cycle the characteristic temperature points that represent phase nucleation and growth are established. Once characteristic temperatures in the alloy samples are known, strategic quench points can be chosen to reveal the evolving mushy state using metallographic examination. In particular the growth kinetics of primary á-Al dendrites in quenched and unquenched alloys are studied and discussed in this work. In addition, growth modes for the Al-Si eutectic lamellae and polyhedral Si particles were also observed from quenched test samples during and post the Al-Si nucleation temperature event.
Aluminum in the Transportation Industry (20082835)
Proceedings of the Third International Conference on Light Metals Technology Sept 24-26 2007 Quebec, Canada P20-25
This paper gives an overview of past, current and future applications of aluminum components in the transportation industry. The different sectors of ground transportation are described with respect to their aluminum usage. Following this is an overview of the various downstream aluminum transformation processes. Typical application examples in the transportation sector are given. Emphasis is placed on where current new developments are focusing and where we can see the future going. Examples of current and future challenges for both aluminum alloys and transformation processes are given as well as what possible solutions may look like.
CONTROLLING ALUMINUM GAS POROSITY (20072121)
Modern Casting V 96 N 1 P 46, Jan 2006 (1 p)
Molten aluminum is vulnerable to picking up hydrogen and at solidification this hydrogen is released forming gas porosity in the casting. The primary source for hydrogen is water vapor. A graph shows the very good correlation between humidity and casting scrap, with the months of May-August being the major problem months. Good foundry practice dictates the avoidance of all conventional moisture sources. However, ultimately, degassing of the molten aluminum is often the required practice needed to produce quality castings. This is accomplished with a rotary degassing device in conjunction with a purge gas. The easily conducted reduced pressure test (RPT) can be used to evaluate the condition of the molten aluminum on the shop floor.
Phase Formation in Multicomponent Monotectic Aluminum Alloys (20082841)
Proceedings of the Third International Conference on Light Metals Technology Sept 24-26 2007 Quebec, Canada P58-59
A classification of monotectic Al-alloys is presented briefly. For the ternary systems Al-Bi-Zn and Al-Cu-Sn calculated liquidus surfaces are shown.
EXPERIMENTAL APPLICATION OF A HIGH VELOCITY COMBUSTION SYSTEM ON A DOUBLE CHAMBER DRY HEARTH REVERBERATORY ALUMINUM FURNACE (19840545)
Transactions of the American Foundrymen's Society V 91 Paper 83-172 P 815-820, 1983 (6 pages)
Targeted at a reduction of energy costs, a high velocity (forced convection) combustion chamber was constructed to evaluate its effect on fuel consumption in melting aluminum 356 alloy. The furnace alterations are shown in line drawings and photos and detailed schematics show the combustion system control circuits and components. Basically, this 1500 lb/hr. furnace showed a fuel savings of 40% average (percentage increases as furnace approaches maximum capacity) after the high velocity combustion system was installed. The high velocity burner sizes is reduced due to the forced convection characteristics.
ALUMINUM PATTERN CASTINGS (3218)
Transactions of the American Foundrymen's Society V 69 P 479-482, 1961 (4 p)
Aluminum patterns and core boxes have the advantages
of light weight, good machinability, high conductivity
of heat and generally satisfactory resistance
to abrasion. Problems have been encountered occasionally
in obtaining aluminum pattern castings of satisfactory
metallurgical quality. The quality requirements
vary for different types of pattern equipment. Foundry
practices for attainment of the desired quality are discussed
in considering each pattern type, shown in the
EFFECT OF SECTION THICKNESS ON THE TENSILE PROPERTIES OF THIN- SECTION ALUMINUM ALLOY SAND CASTINGS 69-32 (19690852)
AFS Transactions 1969, p. 192-197 Modern Casting (Oct. 1969), p. 192-197
A study of the strength characteristics of thin-section aluminum sand castings was conducted. A special test pattern was designed which contained 6 small test plates disposed around a central hub. The plate thicknesses covered a nominal range from 0.040 to 0.200 in. thick. The castings were counter-gravity poured using a previously described apparatus and data was collected on magnesium-silicide alloys, as well as compositions which are representative of the Al-Cu, Al-Mg and Al-Mg-Zn class of alloys. It was found that of the alloys tested, the ones most suitable for thin-section castings were A356 and 355. The most important conclusions are that the properties of thin-section A356 alloy castings are such that the strength and ductility levels can generally meet the requirements for premium quality castings as defined in Military Specification MIL-A-21180-C.
EFFECT OF VIBRATION ON SOLIDIFICATION OF TRANSPARENT LIQUIDS AND AL-SI ALLOYS (19700793)
AFS TRANSACTIONS 1970, p. 324-331
In an effort to obtain new data regarding the effect of vibration on casting structure, 2 new techniques were developed. The first was to use certain transparent liquids which crystallize like metals as models for showing vibration effects. The second was to solidify Al-Si alloys radially outward from a gas-cooled Cu tube immersed in a crucible. The effects of vibration were then evaluated by vibrating the tube instead of the mold and very long solidification times (20 min) were obtained to magnify the effects of vibration are 1) greatly increased precipitation of primary Si crystals of different shape near the cooling tube and 2) pronounced modification of the eutectic structures from a fan-like colony type to a random orientation of the Si phase.
1–10 of about 13700 matches for aluminum OR al
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