Low melting temperature flux materials for brazing applications and methods of brazing using the same

Patent metadata

Field	Value
Publication number	US-12397380-B2
Application number	US-202217813610-A
Country	US
Kind code	B2
Filing date	Jul 20, 2022
Priority date	Jul 28, 2021
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

Low melting temperature flux materials for brazing applications and methods of brazing using the same are provided. A low melting temperature flux material for brazing applications includes as a majority constituent, a Cs-containing flux material, as a first minority constituent, a eutectic blend composition, and, optionally, as a second minority constituent, a mediating compound. The second minority constituent is present in the low melting temperature flux material in a lesser amount with respect to the first minority constituent.

First claim

What is claimed is:

1. A flux composition for brazing applications comprising:
a cesium (Cs)-containing flux material in an amount of from 80 mol-% to 90 mol-% of the total flux composition; and
a eutectic blend composition including sodium tetrafluoroborate and sodium fluoride, wherein the eutectic blend composition is in an amount of 7 mol-% to 13 mol-% of the total flux composition; and wherein the molar ratio of sodium tetrafluoroborate to sodium fluoride is from 88:12 to 92:8.

2. The flux composition of claim 1 , further comprising a mediating compound, wherein the mediating compound is present in the flux composition in a lesser amount with respect to the eutectic blend composition.

3. The flux composition of claim 2 , wherein the mediating compound is zinc oxide.

4. The flux composition of claim 2 , wherein the mediating compound is present in an amount of 3 mol-% to 7 mol-% of the total flux composition.

5. The use flux composition of claim 3 , wherein the flux composition is in the form of a powder or a paste.

6. The flux composition of claim 4 , wherein the mediating compound is zinc oxide.

7. A method of brazing using the flux composition according to claim 1 comprising:
providing or obtaining two metallic substrates;
providing or obtaining a brazing material;
providing or obtaining the flux composition,
applying the brazing material and the flux composition to a joint area of one of the two metallic substrates; bringing together in contact at the joint area the two metallic substrates;
heating the joint area to a temperature above a melting temperature of the brazing material and above a melting temperature of the flux composition, but below a melting temperature of the two metallic substrates; and
allowing the joint area to cool below the melting temperature of the brazing material and below the melting temperature of the flux composition.

8. The method of claim 7 , wherein the brazing material comprises an aluminum-zinc material.

9. The method of claim 8 , wherein the aluminum zinc material comprises a 98Zn/2Al material.

10. The method of claim 7 , wherein the two metallic substrates comprise an aluminum material or an aluminum alloy material.

11. The method of claim 7 , wherein the flux composition is in the form of a powder or a paste.

12. The method of claim 7 , wherein the flux composition further comprises zinc oxide as a mediating compound in an amount of 3 mol-% to 7 mol-% of the total flux composition.

13. The method of claim 12 , wherein the Cs-containing flux material comprises a cesium-aluminum-fluorine flux material.

Assignees

• Honeywell Int Inc

Inventors

• Rudolph Jürgen Friederich
• Rosenthal Moritz Karl

Classifications

• B23K35/282

  Zn as the principal constituent · CPC title

• B23K35/3605

  Fluorides · CPC title

• B23K35/3606

  Borates or B-oxides · CPC title

• B23K2103/10

  Aluminium or alloys thereof · CPC title

• C22C18/04

  with aluminium as the next major constituent · CPC title