The Boeing Company

Krishnan K Sankaran

Kevin T Slattery

Christopher Shane Huskamp

James B Castle

Henry W Babel

Richard J Lederich

Brian J Sova

An aluminum alloy comprises aluminum, magnesium, scandium, and an enhancing system. The magnesium is from about 0.5 percent to about 10.0 percent by weight based on the aluminum alloy. The scandium is from about 0.05 percent to about 10.0 percent by weight based on the aluminum alloy. The enhancing system is from about 0.05 percent to about 1.5 percent by weight based on the aluminum alloy.

Weldable high-strength aluminum alloys

Disclosed embodiments disclose processes for making shaped metal alloy parts, and deal more particularly with forming features and reducing residual stresses in such parts. Residual stresses introduced into a metal alloy part by heat treatment, which may include solution annealing and quenching, are reduced by processes that plastically deform the part while forming part features. An embodiment comprises: producing a metal alloy blank; subjecting the blank to a process that introduces residual stresses into the blank and plastically deforming the blank to reduce the residual stresses in the blank. Embodiments comprise: subjecting a part to a heat treatment that introduces residual stresses in the part; and age forming the part to shape the part and reduce the residual stresses, incrementally forging at least one feature into the part and reducing the residual stresses in the part, friction welding the part, or gauge rolling the cast part to desired dimensions.

Engineered shapes from metallic alloys

A method for forming an aluminum alloy article having improved mechanical properties using a solid-state joining process in which the problem of ductility reduction is minimized by conducting a thermal exposure treatment prior to solution heat treatment. This thermal exposure treatment, done at a temperature below the solution heat treatment temperature, releases stored energy in the aluminum-alloy material. The aluminum-alloy material then does not have sufficient energy to cause recrystallization and abnormal grain growth during the subsequent solution heat treatment process. The resultant aluminum-alloy material has a restored mechanical strength with only a minor, but acceptable, decrease in original ductility.

Method to improve properties of aluminum alloys processed by solid state joining

A method to increase the toughness of the aluminum-lithium alloy C458 and similar alloys at cryogenic temperatures above their room temperature toughness is provided. Increasing the cryogenic toughness of the aluminum-lithium alloy C458 allows the use of alloy C458 for cryogenic tanks, for example for launch vehicles in the aerospace industry. A two-step aging treatment for alloy C458 is provided. A specific set of times and temperatures to age the aluminum-lithium alloy C458 to T8 temper is disclosed that results in a higher toughness at cryogenic temperatures compared to room temperature. The disclosed two-step aging treatment for alloy 458 can be easily practiced in the manufacturing process, does not involve impractical heating rates or durations, and does not degrade other material properties.

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St. Louis, MO, United States of America

Krishnan K Sankaran