Reducing metals as a brazing flux

• US 6,575,353 B2
• Filed: 02/20/2001
• Issued: 06/10/2003
• Est. Priority Date: 02/20/2001
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Palmgren, Gary M.
• Primary Examiner(s): Elve, M. Alexandra
• Assistant Examiner(s): Kerns, Kevin P.
• Application Number:
  US09/788,784
• Publication Number:
  US 20020155313A1
• Time in Patent Office: 840 Days
• Field of Search: 228/122.1, 228/245, 228/246, 228/254, 228/56.3, 228/194, 228/256
• US Class Current: 228/245
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 35/001 Interlayers, transition pieces for metallurgical bonding of workpieces
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: Y10T 428/12535 with additional, spatially distinct nonmetal component
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12736 Al-base component
• CPC Class Codes: Y10T 428/12979 Containing more than 10% nonferrous elements [e.g., high alloy, stainless]

Abstract

A method for the manufacture of a brazed body including forming a multi-layer assembly having: a first material capable of forming a first oxide and having a melting temperature higher than 660° C.; a first reducing metal adjacent the first material, the reducing metal capable of reducing at least a portion of the first oxide on the first material a braze adjacent to the reducing metal; and a second material adjacent the braze, the second material being a material having a melting temperature higher than 660° C. The method then includes creating a vacuum around the assembly, and heating the assembly to melt the reducing metal and the braze. The assembly is then subject to cooling to thereby form the brazed body.

Claims

1. A method of manufacturing a brazed body comprising

(a) arranging multi-layer assembly comprising

a first metal material having a melting temperature higher than 660°

C. and having a native oxide;

a first reducing metal adjacent the first material, the first reducing metal being a reducing metal for the oxide of the first material;

a braze adjacent to the reducing metal; and

a second material adjacent the braze, the second material comprising a material having a melting temperature higher than 660°

C.;

(b) creating a vacuum around the assembly;

(c) heating the assembly to melt the reducing metal and the braze; and

(d) cooling the assembly to thereby form the brazed body.

2. The method of claim 1 wherein the second material has a native oxide, the assembly further comprising a second reducing metal adjacent the second material, the reducing metal being a reducing metal for the oxide of the second material.

3. The method of claim 1 wherein the first material is a metal selected from stainless steel, titanium, nickel, iron, cobalt, chromium, zirconium, and alloys containing one or more of these.

4. The method of claim 1 wherein the second material is a fused abrasive body.

5. The method of claim 1 wherein the reducing metal is aluminum.

6. The method of claim 1 wherein the braze comprises a material selected from copper, silver, tin, indium and alloys containing one or more of these.

7. The method of claim 1 wherein, at step (b), the vacuum is at least 0.6 Pascal.

8. The method of claim 1 wherein at step (c), the assembly is heated to between about 450°

C. and about 800°

C.

9. The method of claim 1 wherein at step (c), the assembly is heated for a length of time between about 1 minute and about 15 minutes.

10. The method of claim 1 wherein at step (c), the assembly is heated to between about 700°

C. and about 900°

C.

11. The method of claim 10 wherein at step (c), the assembly is heated for a length of time between about 1 minute and about 15 minutes.