Nickel-based brazing foil and process for brazing

Patent metadata

Field	Value
Publication number	US-9757810-B2
Application number	US-28575408-A
Country	US
Kind code	B2
Filing date	Oct 14, 2008
Priority date	Oct 15, 2007
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

Disclosed is an amorphous, ductile brazing foil with a composition consisting essentially of Ni rest Cr a B b P c Si d with 2 atomic percent≦a≦30 atomic percent; 0.5 atomic percent≦b≦14 atomic percent; 2 atomic percent≦c≦20 atomic percent; 0 atomic percent≦d≦14 atomic percent; incidental impurities≦0.5 atomic percent; rest Ni, where c>b>c/15 and 10 atomic percent≦b+c+d≦25 atomic percent. Also disclosed is amorphous, ductile Ni-based brazing foil having a composition consisting essentially of Ni rest Cr a B b P c Si d C e X f Y g wherein a, b, c, d, e, f, and g are numbers such that 2 atomic percent≦a≦30 atomic percent; 0.5 atomic percent≦b≦14 atomic percent; 2 atomic percent≦c≦20 atomic percent; 0 atomic percent≦d≦14 atomic percent; 0 atomic percent≦e≦5 atomic percent; 0 atomic percent≦f≦5 atomic percent; 0 atomic percent≦g≦20 atomic percent; wherein incidental impurities are present, if at all, in amounts≦0.5 atomic percent; wherein rest indicates that the balance of the composition is Ni; wherein c>b>c/15; wherein 10 atomic percent≦b+c+d≦25 atomic percent, wherein X is one or more of the elements Mo, Nb, Ta, W and Cu; and wherein Y is one or both of the elements Fe and Co. Also disclosed are methods for making and using these brazing foils, and brazed objects produced therefrom.

First claim

The invention claimed is:

1. An amorphous, ductile Ni-based brazing foil having a composition consisting essentially of
Ni rest Cr a B b P c Si d
wherein a, b, c, and d are numbers such that 16 atomic percent<a≦30 atomic percent; 0.5 atomic percent≦b≦4 atomic percent; 2 atomic percent≦c≦20 atomic percent; 0 atomic percent<d<14 atomic percent; wherein incidental impurities are present, if at all, in amounts≦0.5 atomic percent; wherein rest indicates that the balance of the composition is Ni; wherein c>b>c/15; and wherein 10 atomic percent≦b+c+d≦25 atomic percent;
wherein the foil has a liquidus temperature of less than 1100° C., the foil varies in thickness from a mean thickness of the foil in a variation of less than 20% over a length of 100 m, the foil has a width B of 30 mm≦B≦150 mm, and the brazing foil is at least 50% amorphous.

2. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the B content b is such that 1 atomic percent≦b≦4 atomic percent.

3. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the P content c is such that 5 atomic percent≦c≦18 atomic percent.

4. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the brazing foil is at least 80% amorphous.

5. The amorphous, ductile brazing foil in accordance claim 1 , wherein the foil has a thickness D of 15 μm≦D≦75 μm.

6. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the foil varies in thickness from a mean thickness of the foil in a variation of less than 25% over a length of 200 m.

7. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the foil varies in thickness from a mean thickness of the foil in a variation of less than 10% over a length of 5000 m.

8. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the foil varies in thickness from a mean thickness of the foil in a variation of less than 15 μm over a length of 100 m.

9. The amorphous, ductile brazing foil in accordance with claim 1 , wherein the liquidus temperature of the foil is less than 1080° C.

10. The amorphous, ductile brazing foil in accordance with claim 9 , wherein the liquidus temperature of the foil is less than 1050° C.

11. A brazed object having a first part joined to a second part by a solder seam produced by heating the brazing foil of claim 1 .

12. The brazed object in accordance with claim 11 , wherein both the first part and the second part are made of a stainless steel.

13. The brazed object of claim 12 , wherein the brazed object is a heat exchanger.

14. The brazed object in accordance with claim 11 , wherein the solder seam has a thickness that is >15 μm.

15. The brazed object of claim 14 , wherein the brazed object is a heat exchanger.

16. The brazed object in accordance with claim 11 , wherein the brazed object is a heat exchanger.

17. The brazed object of claim 16 , wherein the heat exchanger is an exhaust gas recirculation cooler or an oil cooler.

18. The amorphous ductile brazing foil according to claim 1 , wherein 0.5 atomic percent≦b≦3 atomic percent.

19. The amorphous ductile brazing foil according to claim 18 , wherein 0.5 atomic percent≦b≦2.5 atomic percent.

20. The amorphous ductile brazing foil according to claim 19 , wherein 1.5 atomic percent≦b≦2.5 atomic percent.

21. The amorphous, ductile brazing foil in accordance with claim 1 , wherein 16 atomic percent≦a≦20 atomic percent, and 2 atomic percent≦c≦10 atomic percent.

22. A process for joining by fusion two or more parts comprising:
inserting of a brazing foil in accordance with claim 1 between two or more parts to be joined, wherein the parts to be joined have a higher melting temperature than that of the brazing foil to form a solder joint;
heating the solder joint to a temperature above the liquidus temperature of the brazing foil to form a heated solder joint;
cooling the heated solder joint, thereby forming a brazed joint between the parts to be joined.

23. The process in accordance with claim 22 , wherein the heating of the solder joint to a temperature above the liquidus temperature of the brazing foil is carried out in inert gas.

24. The process in accordance with claim 22 , wherein the heating of the solder joint to a temperature above the liquidus temperature of the brazing foil is carried out in a continuous furnace.

Assignees

• Hartmann Thomas
• Nuetzel Dieter
• Vacuumschmelze Gmbh & Co Kg

Inventors

• Hartmann Thomas
• Nuetzel Dieter

Classifications

• C22C1/11

  Making amorphous alloys · CPC title

• Y10T428/12944

  Ni-base component · CPC title

• C22F1/002

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• B23K35/3033

  Ni as the principal constituent · CPC title

• F28F21/089

  Coatings, claddings or bonding layers made from metals or metal alloys (F28F19/06 takes precedence) · CPC title