Comalco Aluminium Limited

Lockheed Missiles & Space Company, Inc.

Kaiser Aluminum Chemical Corporation

Comalco Aluminum Limited

Donald Webster

Donald D Crooks

Aldo E Vidoz

Aluminum-based products are disclosed which contain 0.5 to 4.5 wt % lithium and which further contain no more than 1 ppm of each of the alkali metal impurity elements sodium, potassium, rubidium, and cesium. The products are capable of being aged to a peak-aged condition at which they have a grain boundary region substantially free of liquid phase eutectics comprised of sodium and potassium that form embrittlement phases at room temperature, and have a higher fracture toughness than a similar product containing more than 5 ppm in total of the alkali metal impurity elements.

Aluminum-lithium, aluminum-magnesium and magnesuim-lithium alloys of

A substantially lithium-free aluminum base alloy product having improved combinations of elongation and fracture toughness in an aged condition, the aluminum alloy product comprising at least 0.5 wt. % magnesium; 0.01 to 1 ppm Na; 0.01 to 1 ppm K; less than 0.1 ppm Rb; and less than 0.1 ppm Cs, the remainder comprising aluminum, the amount of Na, K, Rb and Cs measured by GDMS, the product in an aged condition having a grain boundary region substantially free of liquid phase eutectics comprised of Na and K that form embrittlement phases at room temperature; and an increase in fracture toughness compared to an aluminum magnesium alloy having greater amounts of Na, K, Rb and Cs.

Aluminum-magnesium alloys having high toughness

A process for preparing a high strength magnesium alloy comprising heating a melt comprised of a base metal of magnesium, greater than 0.5% of lithium, and at least one alkali metal impurity selected from the group consisting of sodium, potassium, rubidium and cesium, the total alkali metal present in an amount greater than 5 ppm, to a temperature of about 50.degree. to 200.degree. C. above the melting point of alloy being refined in a vacuum for a sufficient time to reduce the aggregate concentration of alkali metal impurities in the melt to less than about 5 ppm as measured by GDMS.

Magnesium-lithium alloys of high toughness

Aluminum-base alloys in a peak-aged condition and magnesium-base alloys in the form of cast products and wrought products capable of having improved combinations of yield strength and fracture toughness are disclosed. The aluminum-base alloy products are comprised of 0.5 to 4.5 wt %. lithium, about 0.01 to 1 ppm Na, about 0.01 to 1 ppm K, less than 0.1 ppm Rb, less than 0.1 ppm Cs, and the remainder comprising aluminum. Aluminum-base alloy products in a peak-aged condition have: (i) a grain boundary region substantially free of liquid phase eutectics comprised of Na and K that form embrittlement phases at room temperature; and (ii) an increase in fracture toughness compared to an aluminum-lithium alloy having greater than 5 ppm aggregate alkali metal.

Aluminum-lithium, aluminum-magnesium and magnesium-lithium alloys of

The toughness of Al-Li, Al-Mg and Mg-Li alloys is increased by a melting and refining process designed to reduce the concentration of alkali metal impurities below specified levels. The hydrogen and chlorine gas constituents are also significantly reduced.

Process for making aluminum-lithium alloys of high toughness

The toughness of Al-Li, Al-Mg and Mg-Li alloys is increased by a melting and refining process designed to reduce the concentration of alkali metal impurities below about 1 ppm and preferably below about 0.1 ppm. The hydrogen and chlorine gas constituents are also significantly reduced.

High strength and high toughness are combined in an aluminum-based metallic product by dispersing particles of an aluminum-based metal having a toughness of at least about 20 foot-pounds through a matrix of aluminum-based metal having a yield strength of at least about 30 ksi.

Aluminum-based composite product of high strength and toughness

A method for enhancing the mechanical properties of cast beryllium and beryllium alloy bodies by reducing beryllium grain size. More particularly, grain size is reduced by forming a metal beryllide phase that is soluble in molten beryllium but of limited solubility in the solid metal. Initially, molten beryllium is cast into a mold and solidified resulting in precipitation of the metal beryllide in the form of finely divided particles at the beryllium grain boundaries. The cast body is then mechanically worked below its recrystallization temperature to form an unstable, deformed microstructure which is converted to a fine grain microstructure during a subsequent anneal above the recrystallization temperature of the beryllium or beryllium alloy body. The anneal can be a separate operation or a continuation of the plastic deformation operation.

Fine grain beryllium bodies

A method for making high ductility beryllium bodies by controlling beryllium oxide particle growth during hot pressing of beryllium powder to a maximum median size of 150 nm. More particularly, particle size is controlled by utilizing starting beryllium powder containing a maximum total concentration of aluminum, silicon and magnesium of 200 ppm and consolidating the powder at a maximum temperature of 1400.degree. F. Ductility is also enhanced by utilizing starting beryllium powder containing a maximum beryllium oxide volume fraction of 1.6 percent and annealing the consolidated powder at temperatures of from 2000.degree. to 2250.degree. F. The anneal can be a separate operation or a continuation of the hot pressing operation.

Method for making high ductility beryllium bodies

A method for enhancing the mechanical properties of beryllium and beryllium alloy bodies by deforming and recrystalizing cast and hot pressed beryllium bodies to a finer grain microstructure than initially present in the bodies without introducing a pronounced crystallographic texture into the bodies. More particularly, the beryllium body undergoes a textureless forging process by which the body is plastically deformed at elevated temperatures with the resulting metal flow being restricted to only one axis of the body. The deformed body is then restored to essentially its original shape and annealed at its recrystalization temperature with a resulting refinement in grain size to a size smaller than that present in the initial body.

Growing community of inventors

Saratoga, CA, United States of America

Donald Webster