# US 4,397,696 A · Method for producing improved aluminum conductor from direct chill cast ingot

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- Number: US 4,397,696 A
- Document ID: US4397696A
- Status: Granted
- Kind: A
- Application number: 06/334,654
- Filed: 1981-12-28
- Granted: 1983-08-09
- Earliest claimed: 1981-12-28
- Assignees: Aluminum Company of America
- Inventors: Asuri K. Vasudevan
- Web page: https://patentgrep.com/patent/US4397696A

## CPC

- C22F 1/04: of aluminium or alloys based thereon
- C22F: CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass, C23F17/00)

## Abstract

Aluminum conductor is made from direct chill cast (DC) ingot with improved conductivity and creep resistance by heating an aluminum-base alloy ingot containing not more than 0.40 wt. % and preferably not more than 0.30 wt. % Fe or a mixture of Mg, Ni or Zr with Fe to a temperature of 400.degree. to 600.degree. C., hot rolling the ingot in this temperature range and then further hot rolling at a reduced temperature range of 175.degree. to 325.degree. C.

## Claims

### Claim 1

A method for the production of an aluminum conductor having improved creep resistance from an aluminum-base alloy ingot containing up to 0.40 wt.% of one of the group consisting of Fe, Mg, Ni, Cu, Si and Zr and not more than 0.9 wt.% when more than one of these elements are present and cast by the direct chill casting process which comprises:
(a) heating the aluminum-base alloy ingot to a temperature of from about 400.degree. to 640.degree. C. and maintaining the ingot at this temperature for from 1/2 to 10 hours;
(b) hot rolling the ingot at a first temperature of 400.degree. to 600.degree. C.; and
(c) hot rolling the ingot at a second temperature of 175.degree. to 325.degree. C.

### Claim 2 (depends on 1)

The method of claim 1 wherein the iron content is not more than 0.40 wt.%.

### Claim 3 (depends on 1)

The method of claim 1 wherein the iron content is from 0.02 to 0.30 wt.%.

### Claim 4 (depends on 1)

The method of claim 1 wherein the total Mg, Ni, Cu, Si and Zr content does not exceed 0.50 wt.%.

### Claim 5 (depends on 1)

The method of claim 1 wherein the ingot is initially heated and rolled in a temperature range of 500 to 600.degree. C.

### Claim 6

A method for producing, from an aluminum-base alloy direct chill cast ingot containing not more than 0.30 wt.% iron, an aluminum conductor characterized by a conductivity of at least 62% of the International Annealed Copper Standard and a 10 year predicted creep strain of less than 1000 microinches per inch comprising:
(a) heating the ingot to a temperature of at least 400.degree. C. to dissolve a portion of said iron;
(b) hot rolling the ingot at a temperature of at least 400.degree. C. to precipitate at least a portion of said iron as FeAl.sub.3 ; and
(c) thereafter hot rolling the ingot at a temperature of not more than 325.degree. C.

### Claim 7 (depends on 6)

The process of claim 6 wherein the ingot is rolled as soon as it reaches the initial temperature.

### Claim 8 (depends on 6)

The process of claim 6 wherein the ingot is maintained in step (a) at an initial temperature of from 400.degree. to 600.degree. C. for from 30 minutes to 10 hours.

### Claim 9 (depends on 8)

The process of claim 8 wherein the ingot is maintained in step (a) at the initial temperature for at least four hours.

### Claim 10 (depends on 9)

The process of claim 9 wherein the hot rolling commences at the same initial temperature as in step (a).

### Claim 11 (depends on 10)

The process of claim 10 wherein the final temperature in step (c) is from 175.degree. to 325.degree. C.