Collaborative Development of a Functional Trivalent Chromium Electroplating Process

Abstract

Faraday has been working for over 20 years on the development of a functional chromium plating process from a trivalent-based electrolyte to replace hexavalent chromium plating. Hexavalent chromium plating has been used for many decades to provide 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 have equivalent functional properties to the 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, and with no hexavalent chromium formation in the bath. The data that will be presented demonstrate the feasibility of the process and have provided the basis for further technical qualification and prototype design. Of note, due to the promise of this technology, Faraday’s team received a 2013 Presidential Green Chemistry Challenge Award. The long development time frame of 20+ years for development, testing and adoption of a new coating process is not uncommon in the aerospace industry, the primary target of Faraday’s trivalent chromium plating process. This is due, in part, to rigorous testing requirements. In addition, the development of a paradigm shifting innovation can be an arduous and lengthy process. The initial phases of this development process were conducted by Faraday under EPA SBIR funding, with some input from academic and government laboratory sources for plating chemistry development. As we presented the data at technical conferences showing the demonstration of feasibility, we began to garner interest from OEMs such as The Boeing Company and depot-level maintenance communities within the Department of Defense. Such interest is vital to furthering technology development, by better understanding the industrial and military needs with respect to testing requirements, as well as implementation restrictions. We obtained funding through a government/industry consortium, the National Center for Manufacturing Sciences, to pass some general tests that needed to be passed to show the functional performance of the coating. During this program, we determined that there are also specific tests for each application, e.g., aerospace versus automotive, and within each application, tests that are specific to each entity, e.g., from one OEM to another and the various services within the Department of Defense. These specific technical hurdles needed to be passed before additional interest, and funding, could be obtained. Furthermore, realizing that plating industry sales are made mostly through chemical vendors, we identified and partnered with a vendor, Coventya, that has the requisite market channels and expertise to sell our trivalent chromium plating process. Coventya is working with us to stabilize the bath chemistry and determine bath lifetime and reliability. We recently began working on a US Army program for an expanded testing matrix working on a fully REACH-compliant trivalent chromium plating chemistry, developed in conjunction with Coventya, that does not contain boric-acid. Acknowledgements: This study is supported by the US EPA SBIR Program (EP-D-11-044), the US Army (W911NF-11-2-0014) and private sources. The financial support of Faraday Technology, Inc. corporate R&D is also gratefully acknowledged.