PROCESS FOR BRAZING WORKPIECES OF ALUMINUM CONTAINING MATERIAL

• US 3,811,177 A
• Filed: 08/29/1972
• Issued: 05/21/1974
• Est. Priority Date: 12/15/1969
• Status: Expired due to Term

• Current Assignee: Heinz Schoer, Werner Schultze
• Original Assignee: Heinz Schoer, Werner Schultze
• Inventors: Schoer, Heinz, Schultze, Werner
• Primary Examiner(s): Overholser, J. Spencer
• Assistant Examiner(s): Shore, Ronald J.
• Application Number:
  US05/285,100
• Time in Patent Office: 630 Days
• Field of Search: 29/494,495,504 75/148,147,146,140,141,142,143,178A
• US Class Current: 228/219
• CPC Class Codes: B23K 35/282 Zn as the principal constituent
• CPC Class Codes: B23K 35/286 Al as the principal constituent

Abstract

A process for brazing aluminum-containing work-pieces wherein the brazing filler metal contains components which lower the surface tension and the viscosity of the molten brazing filler metal, and which lower the interfacial tension between the brazing filler metal and the aluminum-containing work-pieces. Useful components are Bi, Sr, Ba, Sb and Be. The brazing filler metal may be used with or without flux.

Claims

2. In a process as defined in claim 1, wherein said filler metal contains 0.002-0.1 percent by weight of Be.

3. In a process of brazing aluminum-containing workpieces, the step of brazing said workpieces with a filler metal consisting essentially of 4-20 percent by weight of Si, 0.00001-1.0 percent by weight of Be, and 0.01-10 percent by weight of at least one substance selected from the group consisting of Bi, Sr, Ba and Sb, the remainder being substantially Al, said Bi, Sr, Ba, Sb and Be lowering the viscosity and surface tension of the filler metal in its molten state and substantially decreasing the interfacial tension between the molten filler metal and said workpieces, and said step being performed without a flux and in a substantially non-oxidizing atmosphere.

4. In a process as defined in claim 3, wherein said filler metal contains 0.002-0.1 percent by weight of Be.

5. In a process as defined in claim 3, wherein said filler metal contains 0.05-2 percent by weight of said at Least one substance.

6. In a process of brazing aluminum-containing workpieces, the step of brazing said workpieces with a filler metal consisting essentially of 4-20 percent by weight of Si, 0.00001-1.0 percent by weight of Be, and at least one element selected from the group consisting of Cu, Mg, Ni, Sn, Zn and Cd, the remainder being substantially Al, and where present said Cu constituting 0.05-4.7 percent by weight of said filler metal, said Mg constituting 0.05-10 percent by weight of said filler metal, said Ni constituting 0.03-4 percent by weight of said filler metal, said Sn constituting 0.03-12 percent by weight of said filler metal, said Zn constituting 9.3-10.7 percent by weight of said filler metal, and said Cd constituting 0.03-12 percent by weight of said filler metal, said Be lowering the viscosity and surface tension of said filler metal in its molten state and substantially decreasing the interfacial tension between the molten filler metal and said workpieces, and said step being performed without a flux and in a substantially non-oxidizing atmosphere.

7. In a process as defined in claim 6, wherein said filler metal contains 0.002-0.1 percent by weight of Be.

8. In a process of brazing aluminum-containing workpieces, the step of brazing said workpieces with a filler metal consisting essentially of 4-20 percent by weight of Si, 0.00001-1.0 percent by weight of Be, 0.01-10 percent by weight of at least one substance selected from the group consisting of Bi, Sr, Ba and Sb, and at least one element selected from the group consisting of Cu, Mg, Ni, Sn, Zn and Cd, the remainder being substantially Al, and where present said Cu constituting 0.05-4.7 percent by weight of said filler metal, said Mg constituting 0.05-10 percent by weight of said filler metal, said Ni constituting 0.03-4 percent by weight of said filler metal, said Sn constituting 0.03-12 percent by weight of said filler metal, said Zn constituting 9.3-10.7 percent by weight of said filler metal, and said Cd constituting 0.03-12 percent by weight of said filler metal, said Bi, Sr, Ba, Sb and Be lowering the viscosity and surface tension of said filler metal in its molten state and substantially decreasing the interfacial tension between the molten filler metal and said workpieces, and said step being performed without a flux and in a substantially non-oxidizing atmosphere.

9. In a process as defined in claim 8, wherein said filler metal contains 0.002-0.1 percent by weight of Be.

10. In a process as defined in claim 8, wherein said filler metal contains 0.05-2 percent by weight of said at least one substance.

11. In a process as defined in claim 1, wherein said filler metal contains 12.1 percent by weight of Si, 0.10 percent by weight of Mn, 0.02 percent by weight of Mg, 0.38 percent by weight of Fe, 0.02 percent by weight of Ti, 0.01 percent by weight of Cu, 0.04 percent by weight of Zn, and 0.004 percent by weight of Be, the remainder being substantially aluminum.

12. In a process as defined in claim 1, wherein said filler metal contains 7.4 percent by weight of Si, 0.06 percent by weight of Mn, 0.03 percent by weight of Mg, 0.48 percent by weight of Fe, 0.02 percent by weight of Ti, 0.03 percent by weight of Cu, 0.10 percent by weight of Zn, and 0.083 percent by weight of Be, the remainder being substantially aluminum.

13. In a process as defined in claim 3, wherein said filler metal contains 11.9 percent by weight of Si, 0.08 percent by weight of Mn, 0.01 percent by weight of Mg, 0.32 percent by weight of Fe, 0.01 percent by weight of Ti, 0.02 pErcent by weight of Cu, 0.03 percent by weight of Zn, 0.04 percent by weight of Bi, and 0.014 percent by weight of Be, the remainder being substantially aluminum.

14. In a process as defined in claim 3, wherein said filler metal contains 9.8 percent by weight of Si, 0.05 percent by weight of Mn, 0.02 percent by weight of Mg, 0.27 percent by weight of Fe, 0.01 percent by weight of Ti, 0.02 percent by weight of Cu, 0.08 percent by weight of Zn, 0.75 percent by weight of Bi, and 0.036 percent by weight of Be, the remainder being substantially aluminum.