(Invited) Low Wear Index Chromium Coatings Electroplated from a Functional Reach-Compliant Trivalent Chromium Chemistry

Thursday, 5 October 2017: 12:20
Chesapeake G (Gaylord National Resort and Convention Center)
T. D. Hall, E. J. Taylor, M. Inman, S. Snyder, J. Xu, and R. Radhakrishnan (Faraday Technology, Inc.)
Faraday Technology Inc. is a research, development and engineering firm developing electrochemical innovations based has pulse/pulse reverse electrolytic principles [1]. One of Faraday’s current activities is directed towards the development of an innovative REACH-compliant plating process for deposition of functional chrome coatings, based on replacement of the conventional hexavalent chromium plating chemistry with a non-toxic trivalent chromium chemistry. Hexavalent chromium plating has been used for many decades to produce hard, durable coatings with excellent wear and corrosion resistance properties. However, hexavalent chromium has come under increasing scrutiny due to the toxic nature of the bath, effects on the environment, and workers’ health. Faraday has demonstrated that the chrome coatings prepared using the FARADAYIC(R) Process in a trivalent chromium chemistry have equivalent functional properties to chrome coatings produced with a hexavalent chromium bath. The data demonstrates equivalent or superior: 1) plating rate, 2) Knoop hardness, 3) current efficiency, 4) hydrogen embrittlement behavior, 5) adhesion, 6) corrosion resistance, 7) porosity, 8) thickness, 9) Taber Abrasion, Ball on Flat Reciprocating and Dithering wear resistance, with no hexavalent chromium formation in the bath.

This paper will discuss the 2013 EPA Green Chemistry Challenge Award winning work on the development of a REACH-compliant plating process for wear resistant, functional coatings from a single, simple-to-control trivalent-based electrolyte. Specifically, this paper will discuss electrochemical deposition approaches to improve (decrease) the wear index of the chrome coating, to meet the performance from conventional chrome coating processes.

Acknowledgements: This study is supported by the US Army (W911NF-11-2-0014) and private sources.

[1] E. J. Taylor “Adventures in Pulse/Pulse Reverse Electrolytic Processes: Explorations and Applications in Surface Finishing” J. Applied Surface Finsihing, 3(4), 178-189 (2008).