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

Patent metadata

Field	Value
Publication number	US-10161693-B2
Application number	US-201614987387-A
Country	US
Kind code	B2
Filing date	Jan 4, 2016
Priority date	Jul 5, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

An aluminum alloy fin material for heat exchangers, containing 0.5 to 1.5 mass % of Si; more than 1.0 mass % but not more than 2.0 mass % of Fe; 0.4 to 1.0 mass % of Mn; and 0.4 to 1.0 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 1×10 5 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 fin sheet thickness, t (μm), satisfy: 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, comprising 0.5 to 1.5 mass % of Si; more than 1.0 mass % but not more than 2.0 mass % of Fe; 0.4 to 1.0 mass % of Mn; and 0.4 to 1.0 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 1×10 5 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 comprising: 0.5 to 1.5 mass % of Si; more than 1.0 mass % but not more than 2.0 mass % of Fe; 0.4 to 1.0 mass % of Mn; and 0.4 to 1.0 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 1×10 5 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

• C22C21/02

  with silicon as the next major constituent · CPC title

• F28F1/126

  consisting of zig-zag shaped fins (F28F1/105 takes precedence) · CPC title

• C22C21/00

  Alloys based on aluminium · CPC title

• F28F21/084 Primary

  from aluminium or aluminium alloys · CPC title

• B22D11/003

  Aluminium alloys · CPC title