Ceramic Product and Method for Its Manufacture

• US 20120258322A1
• Filed: 11/10/2010
• Published: 10/11/2012
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Original Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Inventors: Drewes, Ulfert, Rossberg, Andreas, Schmidt, Elke, Berlinger, Andrea, Schleiferböck, Detlef
• Granted Patent: US 9,631,995 B2
• Time in Patent Office: Days
• US Class Current: 428/450
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/403 Refractory metals
• CPC Class Codes: C04B 2237/708 of one or more of the interlayers
• CPC Class Codes: C04B 2237/72 Forming laminates or joined articles comprising at least two interlayers directly next to each other
• CPC Class Codes: C04B 37/006 consisting of metals or metal salts
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass

Abstract

A ceramic product 1 includes a first ceramic part 2 and a second ceramic part 3, wherein the first ceramic part 2 is connected with the second ceramic part 3 via a joint, wherein the joint comprises an active hard solder, or braze, characterized in that the joint has an inhomogeneous distribution of the components of the active hard solder, or braze, wherein at least at an interface between the active hard solder, or braze, and the ceramic, the at least one active component of the active hard solder, or braze, is enriched. For manufacture of the product, the active hard solder, or braze, material is provided in such a manner, that at least one surface section of at least one of the ceramic parts is first coated with at least one active component of the active hard solder, or braze, and that on the coated section, an alloy is provided, which, by melting of the alloy during the heating, alloys with the coating and forms a metal joint between the two ceramic parts.

Claims

1-14. -14. (canceled)

15. A method for manufacturing a ceramic product, comprising:

providing a first ceramic part and a second ceramic part;

providing an active hard solder, or braze, material between the first ceramic part and the second ceramic part; and

heating the active hard solder, or braze, in a soldering/brazing process, characterized in that the active hard solder, or braze, material is provided in such a manner, that at least one surface section of at least one of the ceramic parts is first coated with at least one active component of the active hard solder, or braze, and, on the coated section, an alloy is provided, which, by melting of the alloy during the heating, alloys with the coating and forms a metal joint between the two ceramic parts, wherein at least the active component reacts with at least one ceramic part.

16. The method as claimed in claim 15, wherein:

each of the two ceramic parts is coated at least in a surface section with at least one active component of the active hard solder, or braze; and

the alloy is provided between the coated sections of the first ceramic part and the second ceramic part.

17. The method as claimed in claim 15, wherein:

the soldering/brazing process is a vacuum soldering/brazing process or a soldering/brazing process performed with a protective gas.

18. The method as claimed in claim 15, wherein:

the coating with the at least one active component has a thickness of not less than 10 nm, especially not less than 40 nm, and preferably not less than 80 nm.

19. The method as claimed in claim 15, wherein:

the coating with the at least one active component has a thickness of no more than 400 nm, especially no more than 300 nm, and preferably no more than 200 nm.

20. The method as claimed in claim 15, wherein:

the at least one active component comprises especially titanium and/or zirconium, wherein the joint comprises a Zr—

Ni—

Ti alloy.

21. The method as claimed in claim 15, wherein:

at least one of the ceramic parts comprises corundum.

22. A ceramic product, comprising:

at least a first ceramic part and a second ceramic part, wherein;

said first ceramic part is connected with said second ceramic part via a joint;

said joint comprises an active hard solder, or braze, characterized in that, the joint has an inhomogeneous distribution of the components of the active hard solder, or braze; and

at least at an interface between the active hard solder, or braze, and the ceramic, the at least one active component of the active hard solder, or braze, is enriched.

24. The ceramic product as claimed in claim 22, wherein the following pertains:

25. The ceramic product as claimed in claim 22, wherein:

the ceramic product is a pressure sensor, and

the ceramic parts comprise a platform and a measuring membrane.

26. The ceramic product as claimed in claim 22, wherein:

said joint comprises a ternary Zr—

Ni—

Ti alloy with c_Zr mass % Zr, c_Ni mass % Ni and c_Ti mass % Ti, wherein 100>

c_Zr+c_Ni+c_Ti≧

100−

R, with R<

0.5, especially R<

0.3 and preferably R<

0.25.

27. The ceramic product as claimed in claim 26, wherein:

concentrations of components of the alloy lie in the ranges, 55<

c_Zr<

65.5, 20.5<

c_Ni<

27.5 and 14<

c_Ti<

17.5, especially 61<

c_Zr<

63.5, 21.5<

c_Ni<

24 and 14.5<

c_Ti<

15.5.

28. The ceramic product as claimed in claim 26, wherein:

a boundary region is present, in which concentration of aluminum atoms in the active hard solder, or braze, diffused in from the ceramic is larger than the concentration of Ni-atoms in this region; and

this region extends not less than 10 nm, especially not less than 40 nm, and preferably not less than 80 nm from the interface between the ceramic part and the active hard solder, or braze, in the direction of the active hard solder, or braze.