Southwest Research Institute® (SwRI®) News
Printer Friendly VersionSwRI surface modification facility offers two new capabilities
For immediate release.
San Antonio, Texas -- June 28, 2000 -- Southwest Research Institute® (SwRI®) has added both plasma immersion ion implantation and plasma immersion ion processing to its Ion Surface Modification Facility. The new capabilities allow for surface modification at or near room temperature of large, three-dimensional objects.
Plasma immersion ion processing (PIIP), developed at Los Alamos National Laboratory, is a relatively new vacuum technology for the application of hard, wear-resistant coatings. Like conventional physical vapor deposition methods, PIIP is used to deposit various coatings, but the non-line-of-sight PIIP approach allows simultaneous treatment of large components and complex shapes without requiring component manipulation.
The versatility of PIIP for surface modification allows the use of any gas with the same equipment. For example, a single vacuum chamber can use argon gas for sputter-cleaning or nitrogen gas for ion implantation. The same equipment can be used to deposit coatings from hydrocarbon gases or organometallic compounds. PIIP can also be used for deposition of diamond-like carbon (DLC) coatings for roughly the same cost as electro-deposited hard chrome.
Potential applications of PIIP include coating deposition to decrease friction and to improve wear resistance and corrosion resistance. For example, DLC coatings can increase the scuffing resistance of aluminum pistons. Diamond-like carbon also has potential application as a wear-resistant coating for gears, bearings, and seals. Chromium oxycarbide (CrOxCy) coatings have been shown to be resistant to attack by molten aluminum, and thus have potential applications in the aluminum die casting industry.
Plasma immersion ion implantation (PIII) is a patented process developed by the University of Wisconsin. PIII is used primarily for nitrogen implantation to improve the wear resistance of metals and for other implantation processes for the semiconductor industry.
The most common use of PIII is for the nitrogen implantation of electro-deposited hard chrome. PIII has been shown to increase wear life of hard chrome by a factor of two to three and to reduce the friction coefficient by approximately 30 percent.
"With the addition of PIII and PIIP to SwRI's existing capabilities, we can now address larger components (greater than one square meter) and heavier components (more than 500 pounds) than previously possible," says Dr. Kevin Walter, a senior research scientist in SwRI's Mechanical and Materials Engineering Division.
"These are cutting edge technologies that are not yet commercially available, so SwRI is in a unique position to offer these services to U.S. industry," he adds.
SwRI's Surface Modification Facility is the largest and most versatile commercial facility of its kind in North America. In addition to the vacuum chamber used for PIII and PIIP, the facility houses a 120-kilovolt plasma bucket ion source for nitrogen ion implantation of large surface areas and two vacuum chambers for ion beam-assisted deposition of coatings.
For more information about SwRI's surface modification program, contact Deborah Deffenbaugh, (210)-522-2046, Communications Department, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas, 78228-0510, Fax (210) 522-3547.
