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Posted: Oct 28, 2010
Laser technology prevents frictional losses and wear of materials
(Nanowerk News) Lots of energy is lost due to friction. For example, automotive engines would transmit more power, were there no frictional losses in valves, bearings and cylinder heads. Materials scientists at the Saarland University and the Material Engineering Center Saarland (MECS) have therefore come up with a laser technology that allows for precise working on materials' surfaces. The laser beams generate 3-dimensional patterns and change the material's inner structure only at an extremely thin surface layer. This makes the material almost friction-less and less prone to wear.
The scientists were granted the European research award "Honda Initiation Grant", endowed with 30,000 Euros, for their development.
According to different estimations, friction and materials' wear cause an economic loss of five to eight percent of the gross domestic product each year.
"Lots of energy is lost due to friction. In a Diesel engine, only a maximum of 30 percent of the fuel is directly transformed into driving energy", says Frank Mücklich, Professor for Functional Materials at Saarland University and director of the Material Engineering Center Saarland. Also, materials are more strained because of friction which leads to expedited ageing. Many engineers are therefore working on more robust coatings made of ceramics or metal alloys, for example. " However, we have developed a technique to directly influence the materials surfaces and change its structure in order to make it more resistant and offering less friction surface", explains Professor Mücklich.
In the so called Laser interference technology, several bundled laser beams are directed at the material. The laser beams superimpose, similar to the waves that occur when throwing a rock into water. As a result, precise patterns that are only a few nanometers small can be generated on an area of about one square centimeter at once. "The heat hits the surface selectively. We can generate temperatures of almost 4,000 degrees Celsius only at the tenth of a hair's breadth. Right next to it, about five one-thousandth millimeter aside, the surface remains virtually unchanged", says Carsten Gachot, researcher at Professor Mücklich's institute and director of the laser group.