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: EPD11044Title: 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 FARADAYICTM 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 FARADAYICTM process. Finally, a comparative analysis of the technical feasibility and economic benefits of the FARADAYICTM 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 FARADAYICTM 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 FARADAYICTM 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 FARADAYICTM 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 FARADAYICTM process was designed to mimic the existing commercial plating process so that the installation of the FARADAYICTM 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 FARADAYICTM process, due to the increased current efficiency and plating rate as compared to traditional hexavalent chromium plating.
- 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 FARADAYICTM 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 FARADAYICTM 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 projectSupplemental 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 platingRelevant 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 BathThe 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.