Grantee Research Project Results

Final Report: Functional Chrome Coatings on Hard to Access, Internal Surfaces of Industrial Parts from an Environmentally Benign Trivalent Chromium Bath

EPA Contract Number: EPD11044
Title: Functional Chrome Coatings on Hard to Access, Internal Surfaces of Industrial Parts from an Environmentally Benign Trivalent Chromium Bath
Investigators: Hall, Timothy
Small Business: Faraday Technology, Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2011 through August 31, 2011
Project Amount: $80,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2011) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Innovation in Manufacturing

Description:

Functional coatings have been applied to various industrial and commercial parts to enhance the base material's resistance to wear and tarnish. One of the most commonly used coatings is hard functional chrome, which currently is plated from a carcinogenic hexavalent chromium bath. Although there have been many attempts to replace this toxic, wear-resistant coating process with a more environmentally benign manufacturing process, a generic, one-size-fits-all replacement has yet to be identified. Faraday Technology, Inc., proposed a drop-in replacement chromium plating process that can coat complex, hard-to-access surfaces, such as the interior of landing gear, with chrome using an environmentally benign trivalent chromium bath. This green manufacturing process meets the stated EPA needs by improving existing processes while utilizing a novel approach that reduces pollution.

Summary/Accomplishments (Outputs/Outcomes):

In Phase I, a chrome coating was electrodeposited from a trivalent chromium bath onto the inside surface of representative landing gear (i.e., cylindrical steel shafts of varying diameter and length) using a plating apparatus similar to systems currently available in industry. The FARADAYIC^TM processing parameters--that is, the method for trivalent chromium plating--were optimized to control the current distribution during deposition, so as to apply a dense chrome deposit along the length of the cylinder's interior. The coating properties along the length of the shaft were tested for thickness and microstructural uniformity. The physical properties of the coating, specifically adhesion, hardness, and wear resistance, were evaluated using flat coupons coated using the FARADAYIC^TM process. Finally, a comparative analysis of the technical feasibility and economic benefits of the FARADAYIC^TM process as a drop-in replacement was undertaken.

Conclusions:

The work done in this Phase I program demonstrates the feasibility of producing chrome coatings from a benign, trivalent bath onto hard-to-access, interior surfaces of industrial parts using FARADAYIC^TM waveforms. The chrome coating was applied to the internal diameters of 4,130 steel pipes of varying length. The size and length of the pipes evaluated was based on the interest of Faraday's commercial partner, The Boeing Company, and were chosen to evaluate the FARADAYIC^TM process as a drop-in replacement for an in-service,conventional hexavalent chrome plating line. Upon demonstration of a visually uniform coating on the internal surface of 1.5" internal diameter (ID) and 4" long pipes, Faraday scaled up the process to longer lengths (6" and 8") and a larger ID (3"). The data indicated that the physical properties of the chrome coating produced via the FARADAYIC^TM process exhibited similar properties to chrome coatings produced using the conventional hexavalent chromium process in terms of porosity, hardness, and adhesion. Additionally, with the help of Faraday's commercial partner, The Boeing Company, the FARADAYIC^TM process was designed to mimic the existing commercial plating process so that the installation of the FARADAYIC^TM process would simulate a true drop-in replacement. This effort ensured the development of the process to industrial standards. Finally, a head-to-head economic comparison of the two plating processes demonstrated a reduction in the cost per piston coated when using the FARADAYIC^TM process, due to the increased current efficiency and plating rate as compared to traditional hexavalent chromium plating.

Commercialization:

During the Phase I program, Faraday worked with The Boeing Company to obtain its insights on transitioning the technology to industry and potential collaboration on future development efforts. The Boeing Company has an interest in the development of functional chrome coatings from an environmentally benign, trivalent chromium bath due to current and future legislation restricting the use of hexavalent chromium plating lines. Furthermore, by keeping the same coating to replace the hexavalent bath, Boeing anticipates considerable savings in cost related to qualification and design drawings. If development of the technology continues to be successful during the Phase II and Phase III activities, Boeing is willing to perform the necessary reliability and performance testing to help launch the technology into the Boeing product line via either internal captive use or first-tier plating vendors. These activities are aligned with the broader functional coating marketplace.

Additional commercialization activity for this program included the preparation of a Technology Niche Analysis in conjunction with Foresight Science Technology (TNA, Project No. EPA0603TN). The TNA document identified current obstacles for commercialization of the technology as well as previously unidentified end-users that might be interested in the technology developed. One common theme that was shared by the surveyed potential end-users was the need for the FARADAYIC^TM chrome coating to demonstrate similar or superior properties with respect to the current technology (i.e., hexavalent chrome plating) to secure commercialization partners throughout the diverse chrome plating industry. Furthermore, the report indicates that experts and end-users conveyed three key factors associated with bringing the FARADAYIC^TM trivalent process technology to the marketplace:

The main driver behind this technology is worker safety.
Definite needs for this technology exist, as there are technical limitations to existing wear-resistant coating replacement technologies, e.g., high-velocity oxygen fuel (HVOF) spraying requires strictly line-of-site parts or new coating materials that must undergo coating qualification and specification processes.
If qualification data clearly show that a chrome coating produced from the FARADAYIC^TM process has good performance, then companies will be reassured by the fact that they are not replacing the coating (chrome), but just the process of depositing the coating, thereby avoiding the challenges and expenses of qualifying new material systems.

Finally, the potential applications of this green chrome plating technology outside the interest of our commercial partner, The Boeing Company, are vast. These applications include printing cylinders, crankshafts, gun barrels, camera parts, kitchen mixers, etc., which are traditionally commercially coated with chrome. Therefore, the FARADAYIC^TM process shows a great commercial potential as a hexavalent chromium replacement throughout the chrome plating industry.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this project

Supplemental Keywords:

small business, SBIR, chromium plating, green chromium plating process, pollution prevention, chrome coating, chromium VI, chromium III, trivalent chromium, hexavalent chromium, hexavalent chromium plating, trivalent chromium plating, environmentally benign chromium plating

Relevant Websites:

http://www.newmoa.org/prevention/p2tech/TriChromeFinal.pdf Exit

SBIR Phase II:

Functional Chrome Coatings on Hard to Access, Internal Surfaces of Industrial Parts from an Environmentally Benign Trivalent Chromium Bath

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.