Eltech Systems Corporation

University of Florida Research Foundation Inc

Gholamreza J Abbaschian

Douglas J Wheeler

Thomas M Clere

Albert L Barnes

Stephen Abeln

A method for manufacturing ceramic/metal or ceramic/ceramic composite articles is disclosed. The articles can be useful for the production of aluminum in fused salt electrolysis cells, as armor plates for the protection against projectiles, cutting tools, or in abrasion resistance applications. The temperature slope of the process if optimized such that one of the reactants in the manufacturing proceeds through peritectic decomposition at a heating rate of low temperature increase for desirably uniform temperature distribution over the reaction mixture. Then the temperature increase is greatly elevated to obtain a reaction sintering condition for avoiding grain growth of undesired reaction products. Elevated temperature reaction sintering conditions can be maintained to decompose undesired components before they are entrapped by the reaction product.

Ceramic/metal or ceramic/ceramic composite article

A method for manufacturing ceramic/metal or ceramic/ceramic composite articles is disclosed. The articles can be useful for the production of aluminum in fused salt electrolysis cells, as armour plates for the protection against projectiles, cutting tools, or in abrasion resistance applications. The temperature slope of the process if optimized such that one of the reactants in the manufacturing proceeds through peritectic decomposition at a heating rate of low temperature increase for desirably uniform temperature distribution over the reaction mixture. Then the temperature increase is greatly elevated to obtain a reaction sintering condition for avoiding grain growth of undesired reaction products. Elevated temperature reaction sintering conditions can be maintained to decompose undesired components before they are entrapped by the reaction product.

Method of manufacturing a ceramic/metal or ceramic/ceramic composite

A composite for protection against armor-piercing projectiles is disclosed. The composite can be a ceramic composite which may be utilized alone or with other materials, e.g., a metallic or plastic base or substrate layer. Composites of AlN with TiB.sub.2, SiC, B.sub.4 C or their mixtures are utilized. These ceramic composites can be prepared by hot pressing, reaction hot pressing, hot isostatic pressing or pressureless sintering. The composite may have well dispersed grains for at least one component, which grains can be interconnected with grains of the second component, and the grains may be of a size less than about five microns. The composite in layer form can have a metallic cover layer.

Composite for protection against armor-piercing projectiles

A method for improving the ductility of aluminum based alloys containing lithium comprising deforming the alloy below about -50.degree. C. so as to achieve a reduction in the cross-sectional area of the alloy of at least about 15%.

Method of making aluminum-lithium alloys with improved ductility

Disclosed are methods, utilizing electromagnetic levitation, for producing low density, porous metal structures and hollow metallic spheres, using particulate material as a starting point. As an initial step, a porous article of sufficient green strength to be substantially self-supporting is formed of a particulate material containing at least one electrically-conductive metal. The green porous article is subjected to an electromagnetic field which has a field strength and frequency sufficient to levitate the green article in space against the force of gravity, and which has a frequency sufficient to induce in the article an eddy current of such intensity to produce heat sufficient to melt the electrically conductive metal, thereby entrapping the pores of the green article and any gases or non-electrically conductive particulate material contained therein. The next steps vary, depending on whether a porous metal structure or a hollow metallic sphere is to be produced. For producing a porous metal structure, the article is cooled at a rate sufficient to solidify the molten metal and produce a low density porous metal structure containing pores which contain any entrapped gases or non-electrically conductive particulate material. For producing a hollow metallic sphere, the heating of the molten article is continued for a time sufficient to expand any gas contained in the pores to a volume such that substantially all of the entrapped pores combine to produce a hollow molten metal sphere, and then the sphere is cooled to solidify the molten metal.

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Gainesville, FL, United States of America

Gholamreza J Abbaschian