Preparation of Aluminum Lithium and Aluminum Magnesium Alloys by Rapid Crystallization under High Specific Pressures.

This invention relates to alloys and more particularly to aluminum alloys. Modern metallurgy has given rise to thousands of new alloys including stainless steel, Ni base superalloys, titanium and aluminum alloys. While these achievements are noteworthy, it is also true that the specific stiffnesses defined as elastic modulus, E, divided by the specific gravity or density, D of all of these alloys are very nearly the same. Thus, the selection of one alloy over any other is based on other considerations such as yield strength, corrosion resistance, formability, weldability, etc. All these properties can be altered or improved by judicious alloying additions while the elastic modulus remains essentially unaffected. The only known alloy system where a substantial gain in specific stiffness is achievable is aluminum-lithium. When alloyed with aluminum, only 3 addition of lithium produces a two-fold advantage.