ALUMINUM ALLOY HEAT EXCHANGER AND METHOD OF PRODUCING REFRIGERANT TUBE USED FOR THE HEAT EXCHANGER

• US 20160332209A1
• Filed: 07/29/2016
• Published: 11/17/2016
• Est. Priority Date: 06/24/2009
• Status: Active Grant

• Current Assignee: Sumitomo Light Metal Industries Limited (UACJ Corporation)
• Original Assignee: Sumitomo Light Metal Industries Limited (UACJ Corporation)
• Inventors: YAMASHITA, Naoki, ITOH, Yasunaga, HISATOMI, Yuji
• Granted Patent: US 10,307,813 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B21D 53/06 of metal tubes
• CPC Class Codes: B23K 2101/14 Heat exchangers
• CPC Class Codes: B23K 35/282 Zn as the principal constituent
• CPC Class Codes: B23K 35/3607 Silica or silicates
• CPC Class Codes: B23K 35/362 Selection of compositions of fluxes B23K35/365, B23K35/368 take precedence
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: C22C 21/02 with silicon as the next major constituent
• CPC Class Codes: C22C 21/10 with zinc as the next major constituent
• CPC Class Codes: C22C 21/14 with silicon
• CPC Class Codes: F28D 2021/0084 Condensers
• CPC Class Codes: F28D 2021/0085 Evaporators
• CPC Class Codes: F28F 1/00 Tubular elements; Assemblies of tubular elements specially adapted for movement F28F5/00
• CPC Class Codes: F28F 19/02 by using coatings, e.g. vitreous or enamel coatings
• CPC Class Codes: F28F 19/06 of metal
• CPC Class Codes: F28F 21/084 from aluminium or aluminium alloys
• CPC Class Codes: F28F 2275/04 by brazing

Abstract

An aluminum alloy heat exchanger is produced by applying a coating material that is prepared by adding a binder to a mixture of an Si powder and a Zn-containing compound flux powder to a surface of an aluminum alloy refrigerant tube, assembling a bare fin that is formed of an Al—Mn—Zn alloy with the refrigerant tube, and brazing the refrigerant tube and the bare fin by heating in an atmosphere-controlled furnace, the refrigerant tube being an extruded product of an aluminum alloy that comprises 0.5 to 1.7% (mass %, hereinafter the same) of Mn, less than 0.10% of Cu, and less than 0.10% of Si, with the balance being Al and unavoidable impurities.

Claims

1. A method of producing an aluminum alloy refrigerant tube that is used in the manufacture of an aluminum alloy heat exchanger, comprising the steps of:

providing an ingot of an aluminum alloy comprising 0.5-1.7 mass % of Mn, less than 0.10% of Cu and less than 0.10% of Si, with the balance being Al and unavoidable impurities;

subjecting the ingot of the aluminum alloy to a homogenization heat treatment that holds the ingot at a temperature of from 400-650°

C. for 4 hours or more; and

hot-extruding the ingot.

2. The method of claim 1, wherein the homogenization heat treatment includes a first-stage heat treatment that holds the ingot at 570-650°

C. for 2 hours or more, followed by cooling the ingot to 200°

C. or less, and a second-stage heat treatment that holds the ingot at 400-550°

C. for 3 hours or more.

3. The method of claim 1, wherein the homogenization heat treatment includes a first-stage heat treatment that holds the ingot at 570-650°

C. for 2 hours or more and a second-stage heat treatment that holds the ingot at 400-550°

C. for 3 hours or more.

4. The method of claim 3, wherein the aluminum alloy refrigerant tube has an aluminum alloy bar fin made of an Al—

Mn—

Zn alloy brazed thereto, the Al—

Mn—

Zn alloy further comprising at least one of 0.001 to 0.10 mass % of In and 0.001 to 0.10 mass % of Sn.

5. The method of claim 4, wherein the homogenization heat treatment includes the first-stage heat treatment, followed by cooling the ingot to 200°

C. or less, and the second-stage heat treatment.