Active brazing solder for brazing alumina-ceramic parts

• US 6,427,900 B1
• Filed: 12/07/1999
• Issued: 08/06/2002
• Est. Priority Date: 07/25/1996
• Status: Expired due to Fees

• Current Assignee: Endress+Hauser GmbH+Co (ENDRESS)
• Original Assignee: Endress+Hauser GmbH+Co (ENDRESS)
• Inventors: Otto, Andreas, Turnsek, Jürgen Peter, Hegner, Frank, Müller, Heinz, Güther, Volker, Breme, Jürgen, Schmidt, Elke Maria
• Primary Examiner(s): Wyszomierski, George
• Assistant Examiner(s): MORILLO, JANELL COMBS
• Application Number:
  US09/455,690
• Time in Patent Office: 973 Days
• Field of Search: 420/422, 420/421, 148/421, 228/121, 228/124.5
• US Class Current: 228/121
• CPC Class Codes: B22F 9/023 Hydrogen absorption
• CPC Class Codes: B23K 35/32 with the principal constituent melting at more than 1550 degrees C
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/127 The active component for bonding being a refractory metal
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 37/006 consisting of metals or metal salts

Abstract

The active brazing solder for brazing ceramic parts of alumina, particularly of high-purity alumina, contains a maximum of 12 wt. % Ti, a maximum of 8 wt. % Be, and less than 16.5 wt. % Fe, the remainder being Zr and any impurities that may be present. The active brazing solder has the following behaviour/features: Brazing temperature: lower than 1,000° C.; the brazed joint is high-vacuum-tight over a long period of time; the coefficient of thermal expansion of the active brazing alloy is substantially identical to that of the alumina ceramic in the entire temperature range covered during the brazing process; the strength of the brazed joint between the two ceramic parts is so high that under tensile loading, fracture will result not at the joint, but in the adjacent ceramic; the pressure resistance of the active brazing solder is greater than 2 GPa; the active brazing solder is very good processable into powders having particle sizes on the order of 10 μm.

Claims

1. A method of forming a brazed joint between a first alumina-ceramic part and a second alumina-ceramic part, comprising the steps of:

applying to a joint formed by said first alumina-ceramic part and said second alumina-ceramic part an active brazing solder consisting essentially of 8.6 wt. % to 12 wt. % titanium, 1 wt. % to 8 wt. % beryllium, 0 wt. % to 16.5 wt. % iron, 63.5 wt. % to 90.4 wt. % zirconium, and a remainder being any impurities;

heating said active brazing solder applied to said joint to a brazing temperature in order to melt said active brazing solder and wet said first alumina-ceramic part and said second alumina-ceramic part with said active brazing solder; and

cooling said active brazing solder after said heating step to an ambient temperature to form said brazed joint between said first alumina-ceramic part and said second alumina-ceramic part.

2. The method of claim 1, wherein said brazing temperature is below 1000°

C.

3. The method of claim 1, wherein said brazing temperature is between 700°

C. and 980°

C.

4. The method of claim 1, wherein the step of applying comprises the step of applying an active brazing paste comprising said active brazing solder to said joint.

5. The method of claim 1, wherein said active brazing solder consists essentially of about 10 wt. % titanium, about 4 wt. % beryllium, and about 86 wt. % zirconium.

6. The method of claim 1, wherein said active brazing solder consists essentially of about 8.6 wt. % titanium, about 4 wt. % beryllium, about 15.8 wt. % iron, and about 71.6 wt. % zirconium.

7. The method of claim 1, wherein said active brazing solder consists essentially of about 8.8 wt. % titanium, about 2 wt. % beryllium, about 16.2 wt. % iron, and about 73 wt. % zirconium.

8. The method of claim 1, wherein said active brazing solder consists essentially of about 8.9 wt. % titanium, about 1 wt. % beryllium, about 16.3 wt. % iron, and about 73.8 wt. % zirconium.

9. A method of forming a brazed joint between a first alumina-ceramic part and a second alumina-ceramic part, comprising the steps of:

applying to a joint formed by said first alumina-ceramic part and said second alumina-ceramic part an active brazing solder comprising about 10 wt. % titanium, about 4 wt. % beryllium, and about 86 wt. % zirconium;

heating said active brazing solder applied to said joint to a brazing temperature in order to melt said active brazing solder and wet said first alumina-ceramic part and said second alumina-ceramic part with said active brazing solder; and

cooling said active brazing solder after said heating step to an ambient temperature to form said brazed joint between said first alumina-ceramic part and said second alumina-ceramic part.

10. A method of forming a brazed joint between a first alumina-ceramic part and a second alumina-ceramic part, comprising the steps of:

applying to a joint formed by said first alumina-ceramic part and said second alumina-ceramic part an active brazing solder comprising about 8.6 wt. % titanium, about 4 wt. % beryllium, about 15.8 wt. % iron, and about 71.6 wt. % zirconium;

heating said active brazing solder applied to said joint to a brazing temperature in order to melt said active brazing solder and wet said first alumina-ceramic part and said second alumina-ceramic part with said active brazing solder; and

cooling said active brazing solder after said heating step to an ambient temperature to form said brazed joint between said first alumina-ceramic part and said second alumina-ceramic part.

11. A method of forming a brazed joint between a first alumina-ceramic part and a second alumina-ceramic part, comprising the steps of:

applying to a joint formed by said first alumina-ceramic part and said second alumina-ceramic part an active brazing solder comprising about 8.8 wt. % titanium, about 2 wt. % beryllium, about 16.2 wt. % iron, and about 73 wt. % zirconium;

heating said active brazing solder applied to said joint to a brazing temperature in order to melt said active brazing solder and wet said first alumina-ceramic part and said second alumina-ceramic part with said active brazing solder; and

cooling said active brazing solder after said heating step to an ambient temperature to form said brazed joint between said first alumina-ceramic part and said second alumina-ceramic part.

12. A method of forming a brazed joint between a first alumina-ceramic part and a second alumina-ceramic part, comprising the steps of:

applying to a joint formed by said first alumina-ceramic part and said second alumina-ceramic part an active brazing solder comprising about 8.9 wt. % titanium, about 1 wt. % beryllium, about 16.3 wt. % iron, and about 73.8 wt. % zirconium;

heating said active brazing solder applied to said joint to a brazing temperature in order to melt said active brazing solder and wet said first alumina-ceramic part and said second alumina-ceramic part with said active brazing solder; and

cooling said active brazing solder after said heating step to an ambient temperature to form said brazed joint between said first alumina-ceramic part and said second alumina-ceramic part.

13. A method of for a brazed joint between a first alumina-ceramic part of a pressure sensor and a second alumina-ceramic part of the pressure sensor, comprising the steps of:

placing said first alumina-ceramic part of said pressure sensor adjacent said second alumina-ceramic part of said pressure sensor to form a joint between said first alumina-ceramic part of said pressure sensor and said second alumina-ceramic part of said pressure sensor;

applying to said joint formed by said first alumina-ceramic part of said pressure-sensor and said second alumina-ceramic part of said pressure sensor an active brazing solder consisting essentially of 8.6 wt. % to 12 wt. % titanium, 1 wt. % to 8 wt. % beryllium, 0 wt. % to 16.5 wt. % iron, 63.5 wt. % to 90.4 wt. % zirconium, and a remainder being any impurities;

heating said active brazing solder applied to said joint to a brazing temperature in order to melt said active brazing solder and wet said first alumina-ceramic part of said pressure sensor and said second alumina-ceramic part of said pressure sensor with said active brazing solder; and

cooling said active brazing solder after said heating step to an ambient temperature to. form said brazed joint between said first alumina-ceramic part of said pressure sensor and said second alumina-ceramic part of said pressure sensor.

14. The method of claim 13, wherein said brazing temperature is below 1000°

C.

15. The method of claim 13, wherein said brazing temperature is between 700°

C. and 980°

C.

16. The method of claim 13, wherein the step of applying comprises the step of applying an active brazing paste comprising said active brazing solder to said joint.

17. The method of claim 13, wherein said active brazing solder consists essentially of about 10 wt. % titanium, about 4 wt. % beryllium, and about 86 wt. % zirconium.

18. The method of claim 13, wherein said active brazing solder consists essentially of about 8.6 wt. % titanium, about 4 wt. % beryllium, about 15.8 wt. % iron, and about 71.6 wt. % zirconium.

19. The method of claim 13, wherein said active brazing solder consists essentially of about 8.8 wt. % titanium, about 2 wt. % beryllium, about 16.2 wt. % iron, and about 73 wt. % zirconium.

20. The method of claim 13, wherein said active brazing solder consists essentially of about 8.9 wt. % titanium, about 1 wt. % beryllium, about 16.3 wt. % iron, and about 73.8 wt. % zirconium.