Furey, Kajdas patent tribology processBy Liz Crumbley
Spectrum Volume 18 Issue 26 - April 4, 1996
An advanced technology for the lubrication of metals and ceramics, developed by Virginia Tech mechanical engineering professor Michael Furey and professor Czeslaw Kajdas of the Warsaw University of Technology, Institute of Chemistry in Poland, has been patented and is in the process of being licensed for commercial applications.
The technology is based on the concept of tribopolymerization first proposed by Furey several years ago and later refined during several years of collaborative research with Kajdas at Virginia Tech. Tribology (from the Greek tribo, to rub) is the study of friction, wear, and lubrication. Tribopolymerization is defined as the planned and continuous formation of protective polymeric films directly on rubbing surfaces by the use of selected monomers capable of forming polymer films "in situ."
Due to the high surface temperatures in regions of contact, and possibly to emission of charged particles, thin polymeric films form in localized areas of greatest wear. These invisible films are continuously formed and replenished only in critical regions of contact and not on other surfaces.
The concept developed by Furey and Kajdas is one of molecular design; it is not centered on the use of one or only a few compounds, but on classes of specific chemical structures. The process works with a variety of surfaces, including metals and ceramics.
Friction, wear, and lubrication of ceramics is important because ceramics can be used at much higher temperatures than alloy steels commonly used in engines and machines. Ceramics also are harder and more resistant to abrasive or erosive wear and they do not corrode. In addition, some ceramics are much lighter in weight than conventional steel-base materials.
Examples of the potential uses of ceramics include ceramic engines for higher temperature operation and greater thermodynamic efficiency, advanced propulsion systems, turbomachinery, gas turbines, aerospace bearings, automotive engine components, cutting and machining of difficult alloys, biomedical (e.g., artificial joints), ceramic heads for magnetic recording, and any tribological system operating under high temperature, abrasive, or corrosive conditions.
Nathan Katz of the U.S. Army Materials Laboratory estimates that if such low heat-loss engines were used in diesel engines, the annual fuel savings would exceed $5 billion in the U.S. alone. Katz estimates that fuel savings in diesel and gas turbine engines could range from 15 to 40 percent.
A barrier to many commercial uses of ceramics is the fact that conventional lubrication methods, which were developed for steel systems, are often ineffective for ceramic systems.
Earlier research conducted by Furey and Kajdas and funded by the National Science Foundation (NSF) and Virginia's Center for Innovative Technology (CIT) found that compounds selected, developed, or synthesized on the basis of the concept of tribopolymerization are strikingly effective for reducing wear and friction for ceramics.
In the liquid phase, the technology developed by Furey and Kajdas brought about wear reductions of 40-80 percent. In the vapor phase (i.e., in nitrogen), wear reductions with ceramics of up to 99 percent and friction reductions of 40-50 percent were observed. Surprisingly, the additives are more effective at higher temperatures.
In 1995, Furey and Kajdas obtained a patent on tribopolymerization as a method of ceramic lubrication. The researchers recently filed three patent applications for use of the concept with both ceramics and metals.
Also in 1995, the U.S. Government's Energy-Related Inventions Program, a joint program of the Department of Energy and the National Institute of Standards and Technology, selected this invention as one of 12 from over 600 applications as an enabling technology for the development of future high-temperature engines. Furey and Kajdas received a $100,000 grant from the program to demonstrate the viability of their concept under higher temperatures and loads.
Triad Investors Corp. recently signed agreements with Virginia Tech and the CIT to fund additional research to promote the further development, licensing, and marketing of tribopolymerization as an effective and innovative approach to lubrication. Triad is funding $100,000 in research in three areas: Novel fuel lubricity additives for two-stoke engines, tribopolymerization as a novel method of lubricating ceramic machining/cutting tools, and vapor phase lubrication of metals and ceramics at high temperatures by tribopolymerization.
With the support of Triad, other applications of this technology are also being explored, including the area of diesel fuel lubricity--a problem of increasing concern since cleaner low-sulfur fuels have inherently poor lubrication characteristics, leading to excessive fuel pump and injector wear. Stefan Strein, an investment associate for Triad, says, "The Furey/Kajdas technology has great potential for development into viable commercial applications."
Furey and Kajdas met at an international conference, after which Kajdas came to Virginia Tech as a visiting professor in 1986. He has returned to carry out joint research with Furey for each of the last 10 summers, as a co-investigator on research grants from the NSF. Furey and Kajdas have presented papers on this work at international tribology conferences in the U.S., Poland, Hungary, Finland, Japan, Australia, and Germany.
Several students have worked with Furey and Kajdas on tribopolymerization research at Virginia Tech, including eight graduate students, a Fulbright scholar from Poland, and five undergraduates, three of whom received summer research fellowships in a program for women and minority engineering students.