Aluminum alloy fin material for heat exchangers, and method of producing the same

Patent metadata

Field	Value
Publication number	US-10145630-B2
Application number	US-201614987137-A
Country	US
Kind code	B2
Filing date	Jan 4, 2016
Priority date	Jul 5, 2013
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

An aluminum alloy fin material for heat exchangers, containing 0.5 to 1.5 mass % of Si; 0.1 to 1.0 mass % of Fe; 0.8 to 1.8 mass % of Mn; and 0.4 to 2.5 mass % of Zn, with the balance being Al and unavoidable impurities, wherein a metallographic microstructure before braze-heating is such that a density of second phase particles having a circle-equivalent diameter of less than 0.1 μm is less than 1×10 7 particles/mm 2 , and that a density of second phase particles having a circle-equivalent diameter of 0.1 μm or more is 5×10 4 particles/mm 2 or more, wherein a tensile strength before braze-heating, TS B (N/mm 2 ), a tensile strength after braze-heating, TS A (N/mm 2 ), and a sheet thickness of the fin material, t (μm), satisfy a relationship: 0.4≤(TS B −TS A )/t≤2.1, and wherein the sheet thickness is 150 μm or less; and a method of producing the same.

First claim

The invention claimed is:

1. An aluminum alloy fin material for heat exchangers, consisting essentially of: 0.5 to 1.5 mass % of Si; 0.1 to 1.0 mass % of Fe; 0.8 to 1.8 mass % of Mn; and 0.4 to 2.5 mass % of Zn, with the balance being Al and unavoidable impurities,
wherein a metallographic microstructure before braze-heating is such that a density of second phase particles having a circle-equivalent diameter of less than 0.1 μm is less than 1×10 7 particles/mm 2 , and that a density of second phase particles having a circle-equivalent diameter of 0.1 μm or more is 5×10 4 particles/mm 2 or more,
wherein a tensile strength before braze-heating, TS B (N/mm 2 ), a tensile strength after braze-heating, TS A (N/mm 2 ), and a sheet thickness of the fin material, t (μm), satisfy a relationship: 0.4 (TS B −TS A )/t≤2.1, and
wherein the sheet thickness is 150 μm or less.

2. A method of producing an aluminum alloy fin material for heat exchangers, comprising:
casting an aluminum alloy raw material consisting essentially of: 0.5 to 1.5 mass % of Si; 0.1 to 1.0 mass % of Fe; 0.8 to 1.8 mass % of Mn; and 0.4 to 2.5 mass % of Zn, with the balance being Al and unavoidable impurities, by a twin roll-type continuous casting and rolling method;
at least one intermediate annealing, in which a first annealing of the intermediate annealing is carried out in two stages at different retention temperatures, a retention temperature of a second stage is higher than a retention temperature of a first stage, the retention temperature of the first stage is 300° C. to 450° C., the retention temperature of the second stage is 430° C. to 580° C.; and
final cold-rolling at a rolling reduction ratio of 20% to 60%, after performing the intermediate annealing;
wherein a metallographic microstructure before braze-heating is such that a density of second phase particles having a circle-equivalent diameter of less than 0.1 μm is less than 1×10 7 particles/mm 2 , and that a density of second phase particles having a circle-equivalent diameter of 0.1 μm or more is 5×10 4 particles/mm 2 or more,
wherein a tensile strength before braze-heating, TS B (N/mm 2 ), a tensile strength after braze-heating, TS A (N/mm 2 ), and a sheet thickness of the fin material, t (μm), satisfy a relationship: 0.4≤(TS B −TS A )/t≤2.1, and
wherein the sheet thickness is 150 μm or less.

3. The method of producing an aluminum alloy fin material for heat exchangers according to claim 2 , wherein a cooling speed from the time point of completion of a retention for annealing of the second stage to 250° C. is set to 50° C./hour or less.

Assignees

• Uacj Corp

Inventors

• Fukumoto Atsushi
• Mochizuki Junichi
• Niikura Akio

Classifications

• C22F1/043

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

• C22C21/10

  with zinc as the next major constituent · CPC title

• C22F1/04

  of aluminium or alloys based thereon · CPC title

• C22F1/00

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title

• C22F1/053

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