Traditionally, metals have been peened by bombarding the material with tiny metal balls, or "shot," to induce a layer of compressive stress at the surface that prevents metal fatigue and reduces corrosion. However, scientists at Lawrence Livermore National Laboratory (LLNL, Livermore, CA) have developed a new way to treat critical aircraft components, such as turbine engine parts. Advanced laser peening produces parts that last longer and reduce costs.
The laser and shock-generation technology treats the surface of metal parts. In the laser peening process, a laser beam generates a 1 million psi pulse on the surface of a metal part. Short bursts of intense laser light create pressure pulses on the metal surface, which generate shock waves that travel into the metal and compress it.