Granted Patent B2

US 12,397,377 · App. 17/758,599 · Granted Aug 26, 2025

Inventors: Bernd Jacoby (Limburg, DE); Fabian Ritz (Ötzingen, DE); Arne Schlegel (Aachen, DE); Steven Kirkham (Ransbach-Baumbach, DE); Axel Alexander Maria Smeyers (Heist op den Berg, BE)

Assignee: NOVELIS KOBLENZ GMBH

B23K35/0238B23K1/0012B23K35/286B32B15/016C22C21/02B23K2101/14

Abstract

Claims (53)

1. An aluminium alloy multi-layered brazing sheet product for brazing in an inert-gas atmosphere without a flux, comprising:

a core layer made of a 3xxx alloy comprising 0.20% to 0.75 wt. % Mg, and provided with a covering clad layer comprising 2 wt. % to 5 wt. % Si on one or both sides of the 3xxx alloy core layer, wherein the covering clad layer comprises less than 0.005 wt. % of Bi; and

an Al—Si brazing clad layer comprising 7 wt. % to 13 wt. % Si positioned between the 3xxx alloy core layer and the covering clad layer,

wherein the covering clad layer has a thickness X 1 and the Al—Si brazing clad layer has a thickness X 2 and wherein X 2 ≥2X 1 .

2. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the 3xxx alloy core layer comprises 0.20% to 0.60% Mg.

3. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the 3xxx alloy core layer comprises 0.20% to 0.30% Mg.

4. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the 3xxx alloy core layer comprises 0.40% to 0.55% Mg.

5. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the covering clad layer comprises less than 0.005 wt. % Li.

6. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the covering clad layer comprises, in wt. %,

Si 2% to 5%;

Fe up to 0.5%;

Mn up to 0.2%;

Cu up to 0.1%;

Zn up to 0.4%;

Ti up to 0.1%;

Mg less than 0.05 wt. %;

Li less than 0.005 wt. %;

inevitable impurities, each <0.05%, total <0.15%, and aluminium.

7. The aluminium alloy multi-layered brazing sheet product according to claim 6 , wherein the covering clad layer has a Si content of 2.5% to 4.0%.

8. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the 3xxx alloy core layer comprises, in wt. %,

0.5% to 1.8% Mn;

0.20% to 0.75% Mg;

up to 1.1% Cu;

up to 0.4% Si;

up to 0.7% Fe;

up to 0.3% Cr;

up to 0.3% Sc;

up to 0.3% Zr and/or V;

up to 0.25% Ti;

up to 1.2% Zn;

unavoidable impurities each up to 0.05% and total up to 0.2%, and aluminium.

9. The aluminium alloy multi-layered brazing sheet product according to claim 8 , wherein the 3xxx alloy core layer has a Si content less than 0.10%.

10. The aluminium alloy multi-layered brazing sheet product according to claim 8 , wherein the 3xxx alloy core layer has a Cu content up to 0.15%.

11. The aluminium alloy multi-layered brazing sheet product according to claim 8 , wherein the 3xxx alloy core layer has a Cu content in a range of 0.15% to 1.1%.

12. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the Al—Si brazing clad layer comprises, in wt. %,

Si 7% to 13%;

Mg up to 0.5%;

Fe up to 0.7%;

Cu up to 0.3%;

Mn up to 0.8%;

Zn up to 2%;

Bi up to 0.3%;

Ti up to 0.25%;

unavoidable impurities each <0.05%, total <0.2%, and aluminium.

13. The aluminium alloy multi-layered brazing sheet product according to claim 12 , wherein the Al—Si brazing clad layer comprises 10% to 13% Si.

14. The aluminium alloy multi-layered brazing sheet product according to claim 12 , wherein the Al—Si brazing clad layer comprises 0.02% to 0.5% Mg.

15. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the aluminium alloy multi-layered brazing sheet product is surface treated with an alkaline or acidic etchant before a brazing step.

16. The aluminium alloy multi-layered brazing sheet product according to claim 1 , wherein the covering clad layer has a thickness X 1 and the Al—Si brazing clad layer has a thickness X 2 and wherein X 2 ≥2.5X 1 .

17. The aluminium alloy multi-layered brazing sheet product according to claim 16 , wherein X 2 ≥3X 1 .

18. A process for producing a braze heat exchanger, comprising the steps of:

providing at least one aluminium alloy multi-layered brazing sheet product according to claim 1 ; and

brazing in a flux-free controlled atmosphere brazing (CAB).

19. The process of claim 18 , wherein the aluminium alloy multi-layered brazing sheet is surface treated with an alkaline or acidic etchant before the brazing step.

Assignments (4)

Priority Claims (2)

Continuity (1)

References Cited (58)

Cited By (1)

US 12,680,767