The Right Lube Job For Superhot Ceramic Engines?
Someday, ceramic engines may replace today's less efficient metal ones. That's because they weigh less--and burn fuel more completely. One problem, though, is finding a lubricant that will withstand the 600C temperatures in a ceramic engine. So far, researchers have relied on phosphoric acid esters. But these fire-resistant lubricants form a highly corrosive acid.
Now, a Rensselaer Polytechnic Institute researcher has come up with a technique that uses a carbon-based gas as a lubricant. Mechanical engineer James L. Lauer sends a pressurized stream of carbon-rich ethylene gas to coat the bearing with a graphite-like slick. Ultimately, he hopes to use unburned hydrocarbons from the car's exhaust as a friction-fighter instead of ethylene.
Still, an ultra-efficient ceramic engine may be some years away. A ceramic engine bearing lubricated with the gas lasted 90% longer than an unprotected part. But while Lauer expects to improve the wear-resistance of his gas, today it effers only 10% of the protection of low-temperature oils.