Brazing Technology for Aluminum Containing Stainless Steel Providing High Electrical Conductivity Joints

­ Executive Summary Oxidation resistive ferritic stainless steels are used in applications such as solid oxide fuel cells where corrosion resistance is needed under extreme environmental conditions. These materials are commonly bonded to other me…

Executive Summary

Oxidation resistive ferritic stainless steels are used in applications such as solid oxide fuel cells where corrosion resistance is needed under extreme environmental conditions. These materials are commonly bonded to other metals or ceramics by methods including brazing where the braze joints need to withstand high-temperature cycling. In some metal-to-metal applications, extremely low joint resistivity is also required after brazing. However, this is difficult to maintain when brazing oxidation-resistant ferritic stainless steel due to its composition. MSU researchers have recently developed a new brazing technology that provides strong braze joints between aluminum-containing ferritic stainless steel and regular ferritic stainless steel while maintaining outstanding electrical conductivity. The technology also provides exceptional braze joints between stainless steel and ceramics. 

Description of the Technology

The technology involves pre applying and sintering a proprietary composition to at least one of the joint surfaces. This modifies the surface energy of the substrate allowing better wetting and flow of the braze material. The pre-applied layer is designed so that it can prevent Al2O3 formation during joint formation when brazing aluminum-containing ferritic stainless steel to regular ferritic stainless steel.

Benefits

  • High strength braze joints (up to 50 MPa for joints between aluminum-containing stainless steel to non-aluminum-containing stainless steel)
  • Low contact resistance (down to 2.60×10-5 Ω•cm2)
  • Excellent durability and stability against delamination and oxidation
  • Strong braze joints between ceramics and stainless steel

Executive Summary

Oxidation resistive ferritic stainless steels are used in applications such as solid oxide fuel cells where corrosion resistance is needed under extreme environmental conditions. These materials are commonly bonded to other metals or ceramics by methods including brazing where the braze joints need to withstand high-temperature cycling. In some metal-to-metal applications, extremely low joint resistivity is also required after brazing. However, this is difficult to maintain when brazing oxidation-resistant ferritic stainless steel due to its composition. MSU researchers have recently developed a new brazing technology that provides strong braze joints between aluminum-containing ferritic stainless steel and regular ferritic stainless steel while maintaining outstanding electrical conductivity. The technology also provides exceptional braze joints between stainless steel and ceramics.

Description of the Technology

The technology involves pre applying and sintering a proprietary composition to at least one of the joint surfaces. This modifies the surface energy of the substrate allowing better wetting and flow of the braze material. The pre-applied layer is designed so that it can prevent Al2O3 formation during joint formation when brazing aluminum-containing ferritic stainless steel to regular ferritic stainless steel.

Benefits

High strength braze joints (up to 50 MPa for joints between aluminum-containing stainless steel to non-aluminum-containing stainless steel)
Low contact resistance (down to 2.60×10-5 Ω•cm2)
Excellent durability and stability against delamination and oxidation
Strong braze joints between ceramics and stainless steel

Applications

General brazing metals to ceramics
Brazing of different metals
Brazing of materials requiring high-temperature electrical contact
Anode side electrical contacts for solid oxide fuel cells
Heaters, furnace panels
Catalytic convertors

Patent Status

In discussion

Licensing Rights

Full licensing rights available

Inventors

Dr. Jason Nicholas, Genzhi Hu

TECH ID

TEC2022-0065

Website

http://msut.technologypublisher.com/technology/46573

Contact Information

TTO Home Page: http://msut.technologypublisher.com

Name: Jon Debling

Title: Technology Manager

Department: MSU Technologies

Email: deblingj@msu.edu