Final Report: Environmentally and Occupationally Safer Hard Chrome PlatingEPA Contract Number: 68D98124
Title: Environmentally and Occupationally Safer Hard Chrome Plating
Investigators: Sunthankar, Mandar
Small Business: IonEdge Corporation
Project Period: September 1, 1998 through March 1, 1999
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (1998) RFA Text | Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Summary/Accomplishments (Outputs/Outcomes):The purpose of this Phase I project is to test and evaluate a novel chromium coating method as an alternative to conventional electroplating. Chromium plating is widely applied to hardware used in the defense, aerospace, transportation, appliance, electronics and other industries. Chromium has a decorative appeal when coated thin, and has a engineering value when coated thick as well as hard. Hard chromium coating imparts wear and corrosion protection to steel components used under heavy load. There are over 1,500 chromium electroplating shops in the U.S. alone, and these are environmentally hazardous because these use carcinogenic hexavalent chromium and generate toxic fumes and mists. In addition, the operations discharge large quantities of effluents and dispose of toxic sludge in regulated land sites.
To address these environmental challenges faced by the chromium plating industry, IonEdge Corporation has embarked on an ambitious project to develop an alternative method which will not only address chromium plating problems but could also be extended to other metals and alloys with further development. This comprehensive approach will provide a solution to several other operations in the electroplating industry and prevent pollution on a wider scale. This Phase I project the results of which are highly promising is considered just one branch of this entire plan.
In order to make the comprehensive approach economical and successful, it was found desirable to adopt a new physical vapor deposition (PVD) technique known for the promise of rapid plating. This PVD will be complemented with pollution prevention methods which were so successfully commercialized by the IonEdge Corporation under its prior SBIR projects.
The objectives of the Phase I have been selected for nearly complete evaluation of the proposed PVD technology and coating property studies so that these could be compared with those required in the market as a desirable alternative. The technology evaluations intended were different process configurations, chromium deposition rates and their dependence on process conditions. The property studies intended were macroparticles (> 2mm size), coating thickness, density and hardness, adhesion to steel and internal stresses. The research was aided by the Lawrence Berkeley National Laboratory (LBNL) of the Department of Energy.
In the performance of this project, not only the proposed objectives have been met but some important advances have been made toward the phase II apparatus. A small replica or bench top unit which could provide insight into the Phase II process and its effect on coatings has been developed at the IonEdge's facility. This has resulted in a more extensive evaluation of the PVD method. Some important clues were obtained from the research regarding process configuration and its effects on macroparticles. This has resulted in refining the process for a successful future scale up. Also, the parts were chromium coated in small batches to simulate conditions anticipated in the Phase II prototype. The process has demonstrated the capability to deposit coatings rapidly for economical plating of parts. At the same time, the rates can be varied methodically within the commercially desirable range.
The properties of the chromium coatings have been studies extensively, including the use of Scanning Electron Microscope (SEM) and x-ray diffraction. It has been demonstrated that the coatings could be grown with decorative finish as well as diffuse reflection which is typical of industrial grade hard chrome. The as-deposited hardness of the coatings is the maximum that can be obtained from the electroplating process only after a high temperature bake. A relationship has been shown between chromium coating thickness and its composite hardness due to substrate effects. A clear relationship has been demonstrated between macroparticles and process configuration. This has helped select the future process. The chromium coatings have been nearly defect free with very high density. The coating adhesion to steel is also very high and the internal stresses are relatively low. In summary, the coating quality requirements of the market as well as those of the industrial specifications have been met using the new plating method.
In order to successfully commercialize the technology, a lot of work still needs to be done in the Phase II. Some of this will include scaling up the apparatus for a commercial customer, processing a reasonable number of parts in batches repeatedly, demonstrating high throughputs while maintaining quality, developing a process for uniform coatings on complex shapes, recycling material waste, studying coating properties and developing a technology profile for marketing. The future benefits to be gained include elimination of hazardous processes and chemicals, a quick two-step plating process, and cost savings in waste treatment and management. It is believed that a typical medium size plating shop could save nearly $250,000 per year just on waste treatment, and be able to get a full return on investment within a couple of years by adopting this new technology. It is also believed that this economics will be the real driving force behind the projected success of this novel method. Besides, IonEdge Corporation has successfully commercialized another SBIR technology in the past that has been generating substantial revenues.