Processing chromium-containing precipitation hardenable copper base alloys

Claim 2

A process for improving both the strength and electrical conductivity properties of copper base alloys, which comprises: a. casting a chromium-containing precipitation hardenable copper base alloy; b. hot working the alloy at a starting temperature of 950°-1000° C to effect the maximum solid solution of all alloying elements; c. rapidly cooling the alloy to maintain said maximum solid solution of all alloying elements; d. cold working the alloy to a total reduction of at least 60%; e. aging said alloy at 400°-500° C for one to 24 hours; f. cold working the alloy to a further total reduction of at least 50%; and g. aging said alloy at 150°-250° C for 1 to 24 hours.

Claim 3

A process for improving both the strength and electrical conductivity properties of copper base alloys, which comprises: a. casting a chromium-containing precipitation hardenable copper base alloy; b. hot working the alloy at a starting temperature of 850°-950° C; c. solution annealing the worked alloy at a solutionizing temperature of 950°-1000° C, for a period of time sufficient to insure the maximum solid solution of all alloying elements; d. rapidly cooling the alloy to maintain said maximum solid solution of all alloying elements; e. cold working the alloy to a total reduction of at least 60%; f. aging said alloy at 400°-500° C for one to 24 hours; g. cold working the alloy to a further total reduction of at least 50%; and h. aging said alloy at 150°-250° C for one to 24 hours.

Claim 4

A process for improving both the strength and electrical conductivity properties of copper base alloys, which comprises: a. casting a chromium-containing precipitation hardenable copper base alloy; b. hot working the alloy at a starting temperature of 850°-950° C; c. solution annealing the worked alloy at a solutionizing temperature of 950°-1000° C, for a period of time sufficient to insure the maximum solid solution of all alloying elements; d. rapidly cooling the alloy to maintain said maximum solid solution of all alloying elements; e. cold working the alloy to a total reduction of at least 60%; f. aging said alloy at 400°-500° C for one to 24 hours; g. cold working the alloy to a further total reduction of at least 50%; and h. aging said alloy at 150°-250° C for one to 24 hours.

Claim 5

A process as in claim 1 wherein said aging of step (e) is accomplished in cycles with said cold working of step (d), where the cycles end with either an aging or a cold working step.

Claim 6

A process as in claim 2 wherein said aging of step (a) is accomplished in cycles with said cold working of step (g).

Claim 7

A process as in claim 1 wherein the alloy is cast at a temperature which ranges between 25° C above the melting point of the alloy up to 1300° C.

Claim 8

A process as in claim 1 wherein said rapid cooling is sufficient to cool the alloy to at least 350° C.

Claim 9

A process as claim 1 wherein the hot working occurs at a temperature of 975°-1000° C.

Claim 10

A process as in claim 2 wherein the alloy is cast at a temperature which ranges between 25° C above the melting point of the alloy up to 1300° C.

Claim 11

A process as in claim 2 wherein said rapid cooling is sufficient to cool the alloy to at least 350° C.

Claim 12

A process as in claim 2 wherein the solutionizing temperature is 975°-1000° C.

Claim 13

A process as in claim 1 wherein said aging in step (e) is at 430°-470° C for 2 to 10 hours.

Claim 14

A process as in claim 1 wherein said aging in step (g) is at 175°-225° C for 2 to 10 hours.

Claim 15

A process as in claim 2 wherein said aging in step (f) is at 430°-470° C for 2 to 10 hours.

Claim 16

A process as in claim 2 wherein said aging in step (h) is at 175°-225° C for 2 to 10 hours.

Claim 17

A process as in claim 1 wherein said process includes the step of fabricating a wrought article from the worked alloy before subjecting said alloy to the aging of step (g).

Claim 18

A process as in claim 2 wherein said process includes the step of fabricating a wrought article from the worked alloy before subjecting said alloy to the aging of step (h).