Non-chromate Passivation for LHE ZnNi
Abstract
Missouri University of Science and Technology (Missouri S and T) collaborated with Dipsol of America (Dipsol) and Boeing Research and Technology (BR and T) to develop and evaluate low contact resistance passivation layers for Department of Defense electrical system components. Specifically, the team examined five different types of passivation layers that were free of hexavalent chromium for low hydrogen embrittlement (LHE) ZnNi coatings. Passivations included a trivalent chromium passivation (TCP or Cr(III)), a Co-Free TCP, and a Modified Co-Free TCP developed at Dipsol as well as two cerium based conversion coatings (CeCCs) developed at Missouri S and T using cerium chloride and cerium nitrate sources. Hexavalent chromium passivation on electroplated ZnNi was used as a reference. Characterization of the electrical, electrochemical, corrosion, and materials performance of the passivation layers was done to evaluate the corrosion performance and electrical resistance after neutral salt spray exposure. The major outcome of this project was to identify the most promising passivation layer(s) that are free of hexavalent chromium and can be used on LHE ZnNi plated electrical connectors for military electrical system components.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2017
- Accession Number
- AD1029080
Entities
People
- Matt O'keefe
Organizations
- Missouri University of Science and Technology