Method for producing aluminum powder alloy products having improved strength properties

Claim 1

A method of producing an improved metal article having improved mechanical properties comprising the steps: (a) providing metal alloy particulate, said alloy being selected to provide strength enhancing dispersed particles capable of degradation at elevated temperatures; and (b) heating said metal to elevated temperature at a rapid heat-up rate and compacting said metal at elevated temperature to a substantially full density compact, said heat-up rate being such that said heating of said metal to elevated temperature is effected in not more than 0.2 hour for each inch of thickness of said compact, thereby improving said compact such that products made therefrom exhibit an improvement of at least 5% in one or more mechanical properties over a product likewise produced except for said heating occurring over a substantially longer time.

Claim 2

A method of producing an improved metal article having improved mechanical properties comprising the steps: (a) providing metal alloy particulate, said alloy being selected to provide strength enhancing dispersed particles capable of degradation at elevated temperatures; and (b) heating said metal to elevated temperature at a rapid heat-up rate and compacting said metal at elevated temperature to a substantially full density compact, said heat-up rate being such that said heating of said metal to elevated temperature is effected in not more than 0.2 hour for each inch of thickness of said compact, thereby improving said compact such that products made therefrom exhibit an improvement of at least 5% in one or more mechanical properties over a product likewise produced except for said heating occurring over a substantially longer time.

Claim 10

A method of producing an improved aluminum article having improved mechanical properties comprising the steps: (a) providing aluminum alloy particulate, said alloy being selected to provide strength enhancing dispersed particles capable of degradation at elevated temperatures above 650° F.; (b) compacting said aluminous particulate at a temperature below 250° F. to form a cohesive self-supporting green compact; (c) rapidly induction heating said green compact in a relatively non-oxidizing atmosphere at a high heat-up rate to an elevated temperature above 650° F., said heat-up rate being such that said heating to said elevated temperature is effected in not more than 0.2 hour per inch of compact thickness; and (d) compacting said induction heated green compact at an elevated temperature above 650° F. to substantially full density; thereby improving said compact such that products made therefrom exhibit an improvement of at least 5% in one or more mechanical properties over a product likewise produced except for the heating recited in step (c) being by external heating at a substantially slower rate over a substantially longer time.

Claim 11

A method of producing an improved aluminum article having improved mechanical properties comprising the steps: (a) providing aluminum alloy particulate, said alloy being selected to provide strength enhancing dispersed particles capable of degradation at elevated temperatures above 650° F.; (b) compacting said aluminous particulate at a temperature below 250° F. to form a cohesive self-supporting green compact; (c) rapidly induction heating said green compact in a relatively non-oxidizing atmosphere at a high heat-up rate to an elevated temperature above 650° F., said heat-up rate being such that said heating to said elevated temperature is effected in not more than 0.2 hour per inch of compact thickness; and (d) compacting said induction heated green compact at an elevated temperature above 650° F. to substantially full density; thereby improving said compact such that products made therefrom exhibit an improvement of at least 5% in one or more mechanical properties over a product likewise produced except for the heating recited in step (c) being by external heating at a substantially slower rate over a substantially longer time.

Claim 31

A method of producing an improved aluminum article having improved strength properties comprising the steps: (a) providing aluminum alloy particulate, said alloy being selected to provide strength enhancing dispersed particles capable of degradation at elevated temperatures above 650° F.; (b) compacting said aluminous particulate at a temperature below 250° F. to form a cohesive self-supporting green compact; (c) rapidly induction heating said green compact in a relatively non-oxidizing atmosphere at a high heat-up rate to a temperature above 700° F., said heat-up rate being such that said heating to said temperature is effected in not more than 0.15 hour per inch of compact thickness; (d) holding said rapidly heated-up compact at a temperature above 700° F.; (e) compacting said induction heated green compact at a temperature above 700° F. to substantially full density; and (f) working said substantially full density compact equivalent to a reduction of at least 25% at a temperature of at least 500° F. to provide a worked product; said worked product exhibiting an improvement of at least 5% in one or more mechanical properties over a like-produced product except for the heating recited in said step (c) being by external heating at a substantially slower rate over a substantially longer time.

Claim 32

A method of producing an improved aluminum article having improved strength properties comprising the steps: (a) providing aluminum alloy particulate, said alloy being selected to provide strength enhancing dispersed particles capable of degradation at elevated temperatures above 650° F.; (b) compacting said aluminous particulate at a temperature below 250° F. to form a cohesive self-supporting green compact; (c) rapidly induction heating said green compact in a relatively non-oxidizing atmosphere at a high heat-up rate to a temperature above 700° F., said heat-up rate being such that said heating to said temperature is effected in not more than 0.15 hour per inch of compact thickness; (d) holding said rapidly heated-up compact at a temperature above 700° F.; (e) compacting said induction heated green compact at a temperature above 700° F. to substantially full density; and (f) working said substantially full density compact equivalent to a reduction of at least 25% at a temperature of at least 500° F. to provide a worked product; said worked product exhibiting an improvement of at least 5% in one or more mechanical properties over a like-produced product except for the heating recited in said step (c) being by external heating at a substantially slower rate over a substantially longer time.