Nippon Light Metal Company, Ltd.

Alcan International Limited

Novelis, Inc.

Yoshito Oki

Hideki Suzuki

Toshiya Anami

Tomohiro Sasaki

Iljoon Jin

Kevin Michael Gatenby

Masae Nagasawa

Haruo Sugiyama

Ichiro Okamoto

Willard Mark Truman Gallerneault

Willard Mark Gallerneault

Toshihiro Suzuki

Tsunehiko Tanaka

Meitoku Ogasawara

Jean-Pierre Martin

A heat exchanger use high strength aluminum alloy fin material having a high strength and excellent in thermal conductivity, erosion resistance, sag resistance, sacrificial anodization effect, and self corrosion resistance, characterized by containing Si: 0.8 to 1.4 wt %, Fe: 0.15 to 0.7 wt %, Mn: 1.5 to 3.0 wt %, and Zn: 0.5 to 2.5 wt %, limiting the Mg as an impurity to 0.05 wt % or less, and having a balance of ordinary impurities and Al in chemical composition, having a metal structure before brazing of a fibrous crystal grain structure, a tensile strength before brazing of not more than 240 MPa, a tensile strength after brazing of not less than 150 MPa, and a recrystallized grain size after brazing of 500 &#x3bc;m or more.

High strength aluminum alloy fin material and method of production of same

A heat exchanger use high strength aluminum alloy fin material having a high strength and excellent in thermal conductivity, elusion resistance, sag resistance, sacrificial anodization effect, and self corrosion resistance, characterized by containing Si: 0.8 to 1.4 wt %, Fe: 0.15 to 0.7 wt %, Mn: 1.5 to 3.0 wt %, and Zn: 0.5 to 2.5 wt %, limiting the Mg as an impurity to 0.05 wt % or less, and having a balance of ordinary impurities and Al in chemical composition, having a metal structure before brazing of a fibrous crystal grain structure, a tensile strength before brazing of not more than 240 MPa, a tensile strength after brazing of not less than 150 MPa, and a recrystallized grain size after brazing of 500 &#x3bc;m or more.

[PROBLEMS] To provide an aluminum alloy fin material for a heat exchanger, which has high strength and high heat conductivity after brazing, and is excellent in the resistance to sagging, erosion and self-corrosion and the in the sacrificial anode effect. [MEANS FOR SOLVING PROBLEMS] A method for producing an aluminum alloy fin material for a heat exchanger which comprises providing a molten aluminum alloy having a chemical composition, in wt %, that Si: 0.5 to 1.5%, Fe: 0.15 to 1.00%, Mn: 0.8 to 3.0%, Zn: 0.5 to 2.5%, with the proviso that the content of Mg as an impurity is limited to 0.05 wt % or less, and the balance: Al and inevitable impurities, casting the molten alloy continuously into a thin slab having a thickness of 5 to 10 mm by the use of a twin belt casting machine, winding up the slab into a roll, cold-rolling the slab into a sheet having a thickness of 0.05 to 2.0 mm, subjecting the sheet to an inter annealing at 350 to 500&#xb0; C., and cold-rolling the annealed sheet with a cold reduction rate of 10 to 96%, to prepare a sheet having a final thickness of 40 to 200 &#x3bc;m, and optionally subjecting the final sheet to a final annealing (a softening process) at a holding temperature of 300 to 400&#xb0; C.

High strength aluminum alloy fin material for heat exchanger and method for production thereof

[PROBLEMS] To provide an aluminum alloy fin material for a heat exchanger, which has high strength and high heat conductivity after brazing, and is excellent in the resistance to sagging, erosion and self-corrosion and the in the sacrificial anode effect. [MEANS FOR SOLVING PROBLEMS] A method for producing an aluminum alloy fin material for a heat exchanger which comprises providing a molten aluminum alloy having a chemical composition, in wt %, that Si: 0.5 to 1.5%, Fe: 0.15 to 1.0%, Mn: 0.8 to 3.0%, Zn: 0.5 to 2.5%, with the proviso that the content of Mg as an impurity is limited to 0.05 wt % or less, and the balance: Al and inevitable impurities, casting the molten alloy continuously into a thin slab having a thickness of 5 to 10 mm by the use of a twin belt casting machine, winding up the slab into a roll, cold-rolling the slab into a sheet having a thickness of 0.05 to 2.0 mm, subjecting the sheet to an inter annealing at 350 to 500&#xb0; C., and cold-rolling the annealed sheet with a cold reduction rate of 10 to 96%, to prepare a sheet having a final thickness of 40 to 200 &#x3bc;m, and optionally subjecting the final sheet to a final annealing (a softening process) at a holding temperature of 300 to 400&#xb0; C.

An improved aluminum alloy fin stock is described having both a high strength and a high thermal conductivity. The fin stock contains 1.2-1.8% Fe, 0.7-0.95% Si, 0.3-0.5% Mn, 0.3-1.2% Zn and the balance Al, and is produced by continuously strip casting the alloy at a cooling rate greater than 10&deg; C./sec. but less than 200&deg; C./sec., hot rolling the strip to a re-roll sheet without homogenization, cold rolling the re-roll sheet to an intermediate gauge, annealing the sheet and cold rolling the sheet to final gauge. This fin stock has a conductivity after brazing of greater than 49.8% IACS.

High conductivity aluminum fin alloy

A method of producing an aluminum alloy fin stock material, comprising the steps of continuously strip casting an aluminum finstock alloy to form an as-cast strip, rolling the as-cast strip to form a sheet article of intermediate gauge, annealing the sheet article of intermediate gauge, and cold rolling the annealed sheet article of intermediate gauge to produce an aluminum finstock material of final gauge. The steps are carried out on a finstock alloy which comprises the following elements in weight percent: Fe 1.6 to 2.4; Si 0.7 to 1.1; Mn 0.3 to 0.6; Zn 0.3 to 2.0; Ti 0.005 to 0.040; incidental elements less than 0.05 each, total no more than 0.15; and the balance aluminum. The invention also relates to the finstock material so-produced which has good thermal conductivity, and is suitable for use in thin gauge (e.g. less than 100 &mgr;m, and preferably 60&plusmn;10 &mgr;m).

High thermal conductivity aluminum fin alloys

By the use of a heat exchanger tube not required for adhesion of Zn in advance and a fin not clad with a brazing composition, a heat exchanger core is provided which has corrosion resistance and brazing capability comparable to or higher than those of the conventional counterpart. Applied onto an outer surface of an extruded flattened tube as a heat exchanger tube is a brazing composition derived from a mixture of silicon and fluorine type flux, and a fin formed of an aluminum-based zinc-containing material is prepared. The extruded flattened tube and the fin are then heated at a given temperature so that the same are brought into brazed relation to each other, and a mixed diffusion layer of silicon and zinc is then on the outer surface of the extruded flattened tube.

Heat exchanger core based on aluminum and process for producing the same

An aluminum alloy fin stock of lower (more negative) corrosion potential and higher thermal conductivity is produced by a process, which comprises continuously strip casting the alloy to form a strip, cold rolling the strip to an intermediate gauge sheet, annealing the sheet and cold rolling the sheet to final gauge. Lower corrosion potential and higher thermal conductivity are imparted by carrying out the continuous strip casting while cooling the alloy at a rate of at least 300.degree. C./second, e.g. by conducting the casting step in a twin-roll caster.

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Shizuoka, Japan

Yoshito Oki