Active brazing material and method for active brazing of components

• US 10,632,555 B2
• Filed: 11/03/2015
• Issued: 04/28/2020
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: Endress+Hauser SE+Co. KG (Endress+Hauser AG)
• Original Assignee: Endress+Hauser SE+Co. KG (Endress+Hauser AG)
• Inventors: Ponath, Nils, Rossberg, Andreas, Schmidt, Elke
• Primary Examiner(s): Saad, Erin B
• Application Number:
  US15/535,080
• Publication Number:
  US 20170348783A1
• Time in Patent Office: 1,638 Days
• CPC Class Codes: B23K 1/0006 Exothermic brazing
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 2103/52 Ceramics
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: B23K 35/286 Al as the principal constituent
• CPC Class Codes: B23K 35/3033 Ni as the principal constituent
• CPC Class Codes: B23K 35/32 with the principal constituent melting at more than 1550 degrees C
• CPC Class Codes: B23K 35/325 Ti as the principal constituent
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: B32B 15/017 one layer being formed of aluminium or an aluminium alloy, another layer being formed of an alloy based on a non ferrous metal other than aluminium
• CPC Class Codes: C23C 14/18 on other inorganic substrates
• CPC Class Codes: G01L 19/00 Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass

Abstract

An active brazing material for the energy-efficient production of active-brazed connections that consists of layer sequences arranged on top of one another, the layer sequences of which consist of layers arranged on top of on another, the layer sequences of which each comprise at least one layer of brazing material, wherein the layers of brazing material of each layer sequence each contain at least one component of a base active braze and, in conjunction with each other, contain all components of the base active braze, the layer sequences of which each comprise at least one first reaction layer consisting of a first reactant to which at least one second reaction layer is directly adjacent in the active brazing material and consists of a second reactant that exothermally reacts with the first reactant, wherein an enthalpy of formation of the exothermic reaction of the reactants is greater than or equal to 45 kJ/mol—in particular, greater than or equal to 50 kJ/mol.

Claims

1. A method for active brazing of components of a ceramic pressure sensor, said pressure sensor comprising:

a ceramic measurement membrane that can be supplied with pressure and elastically deformed as a function of the pressure; and

a ceramic base body;

the method comprising;

producing an active-brazed connection during the active brazing, wherein said active-brazed connection bonds an outer edge of a first side of said measurement membrane to an outer edge of a face side of said base body facing the measurement membrane, thereby including a pressure chamber of said ceramic pressure sensor;

using an active brazing material in the production of said active-brazed connection, said active brazing material comprising;

layer sequences arranged on top of one another, said layer sequences consist of layers arranged on top of one another;

wherein;

said layer sequences each comprise at least one layer of said active brazing material, the layers of said active brazing material of each layer sequence each contain at least one component of a base active braze, and the layers in conjunction with each other, contain all components of said base active braze; and

said layer sequences of which each comprise at least one first reaction layer consisting of a first reactant to which at least one second reaction layer is directly adjacent in said active brazing material and consists of a second reactant that exothermally reacts with said first reactant, an enthalpy of formation of the exothermic reaction of the reactants is greater than or equal to 45 kJ/mol;

wherein the second reactant is a component of said base active braze, said second reaction layers are layers of said brazing material that consist of said respective component,

wherein said base active braze comprises zirconium, nickel, and titanium;

said first reaction layers consist of aluminum; and

said second reaction layers are layers of brazing material made of nickel,

producing an arrangement in which said active brazing material is arranged between joining surfaces of said ceramic base body and said ceramic measurement membrane; and

triggering the exothermic reactions of said first reaction layer and said second reaction layer adjacent to it during the active brazing.

2. The method according to claim 1, wherein:

said layers of said layer sequences have layer thicknesses less than or equal to 10 nm.

3. The method according to claim 1, wherein:

said first reaction layers and said second reaction layers have layer thicknesses less than or equal to 5 nm.

4. The method according to claim 1, wherein:

said first reaction layers and said second reaction layers adjacent to one another have equal layer thicknesses.

5. The method according to claim 1, wherein:

each layer sequence comprises a layer of said brazing material, which consists of said base active braze and on which a reactive layer system is arranged that comprises one of said first reaction layers and said directly adjacent second reaction layer.

6. The method according to claim 1, wherein:

at least one layer of said brazing material consisting of said at least one component of said active braze is contained in each layer sequence for each component of said base active braze; and

a reactive layer system is arranged on at least one of these layers of brazing material that comprises one of said first reaction layers and said directly adjacent second reaction layer.

7. The method according to claim 1, wherein:

at least one of said layers of brazing material consisting of said respective component that reacts exothermally with said first reactant is arranged in each layer sequence in such a manner that it is arranged in said active brazing material between two of said first reaction layers consisting of said first reactant.

8. The method according to claim 6, wherein:

said layers of said brazing material have a layer thickness of less than or equal to 10 nm.

9. The method according to claim 1, wherein:

the exothermic reactions are triggered at a base temperature of said arrangement at which the energy produced by the exothermic reactions is enough to melt the layers of said active brazing material.

10. The method for active brazing of components according to claim 1, wherein:

active brazing material is arranged between joining surfaces in the form of a prefabricated molded part;

or said the active brazing material is applied to one of the joining surfaces;

or

one portion of the active brazing material is applied to each of the joining surfaces.

11. The method according to claim 10, wherein said prefabricated molded part is a film,

or

wherein said active brazing material is applied by consecutive vapor deposition of its layers to be arranged on top of one another.

12. The method according to claim 1, wherein said ceramic measurement membrane is made of aluminum oxide (Al2O3) and said ceramic base body is made of aluminum oxide (Al2O3).