High strength aluminum alloy fin stock for heat exchanger

Patent metadata

Field	Value
Publication number	US-2016195346-A1
Application number	US-201414909798-A
Country	US
Kind code	A1
Filing date	Aug 8, 2014
Priority date	Aug 8, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

The present invention provides an aluminum alloy fm stock alloy material with higher strength, and improved sag resistance for use in heat exchangers. This aluminum alloy fm stock alloy material was made by direct chill (DC) casting.

First claim

1 . An aluminum alloy comprising about 0.8-1.4 wt % Si, 0.4-0.8 wt % Fe, 0.05-0.4 wt % Cu, 1.2-1.7 wt % Mn and 1.20-2.3 wt % Zn with the remainder as Al.

2. The aluminum alloy of claim 1 , comprising about 0.9-1.3 wt % Si, 0.45-0.75 wt % Fe, 0.10-0.3 wt % Cu, 1.3-1.7 wt % Mn and 1.30-2.2 wt % Zn, with the remainder as Al.

3 . The aluminum alloy of claim 1 , comprising about 0.9-1.2 wt % Si, 0.5-0.75 wt % Fe, 0.15-0.3 wt % Cu, 1.4-1.6 wt % Mn and 1.4-2.1 wt % Zn, with the remainder as Al.

4 . The aluminum alloy of claim 1 , further comprising up to 0.2 wt % of one or both of Cr or Zr.

5 . An aluminum alloy fin stock material produced from the aluminum alloy of claim 1 by a process, comprising:
direct chill casting the aluminum alloy into an ingot;
preheating the ingot to 450 to 560° C. for 2 to 16 hours;
hot rolling the preheated ingot;
cold rolling the ingot;
inter-annealing at a temperature of 300-450° C.; and,
after inter-annealing, performing a final cold rolling step to achieve % cold work (%CW) of 25-35%.

6 . The aluminum alloy fin stock material of claim 5 , wherein the ingot is preheated at 480° C. for 2-12 hours.

7 . The aluminum alloy fin stock material of claim 5 , wherein the inter-annealing temperature is 300-400° C.

8 . The aluminum alloy fin stock material of claim 5 , having a minimum ultimate tensile strength of ˜130 MPa, measured after brazing.

9 . The aluminum alloy fin stock material of claim 5 , having a corrosion potential of −700 mV or less, measured after brazing.

10 . A heat exchanger comprising the aluminum alloy of claim 1 or the aluminum alloy fin stock material of claim 5 .

11 . The heat exchanger of claim 10 , wherein the heat exchanger is an automotive heat exchanger.

12 . The heat exchanger of claim 10 , wherein the heat exchanger is a radiator, a condenser or an evaporator.

13 . Use of the aluminum alloy of claim 1 or the aluminum alloy fin stock material of claim 5 for fabrication of heat exchanger fins.

14 . A process for making an aluminum alloy fin stock material, comprising:
direct chill casting the aluminum alloy of claim 1 into an ingot; preheating the ingot to 450 to 560° C. for 2 to 16 hours; hot rolling the preheated ingot; cold rolling the ingot; inter-annealing at a temperature of 300-450° C.; and, after inter-annealing, performing a final cold rolling step to achieve % cold work (%CW) of 25-35%.

15 . The process of claim 14 , wherein the ingot is preheated at 480° C. for 2-12 hours.

16 . The process of claim 14 , wherein the inter-annealing temperature is 300-400° C.

17 . The process of claim 15 , wherein the inter-annealing temperature is 300-400° C.

Assignees

• Novelis Inc

Inventors

• Howells Andrew D
• Gatenby Kevin Michael

Classifications

• C22C21/00

  Alloys based on aluminium · CPC title

• C21D1/26

  Methods of annealing · CPC title

• F28F2215/00

  Fins · CPC title

• F28F2275/04

  by brazing · CPC title

• C22F1/053

  of alloys with zinc as the next major constituent · CPC title