Lawrence Livermore National Lab (LLNL) and Metal Improvement Company (MIC) developed a version (brand) of laser peening that they call LasershotSM Peening. In 1999 a web page appeared on the LLNL website tauting the new technology.
Here is a brief excerpt from the LLNL website:
“The new technology, called the LasershotSM Peening System, is designed to extend the service lifetime of critical metal parts, from aircraft engine fan blades Figure 1 to hip joints, by a factor of three to five times over conventional peening treatments. The process also holds the promise of lighter, stronger products of entirely new designs.
In traditional shot-peening procedures, each metal or ceramic ball acts as a minuscule ball-peen hammer, imparting on a metal surface a small indentation or dimple. This process produces, below the dimple, a hemisphere of highly shocked and compressed material. In time, overlapping dimples provide a very thin about 0.25 millimeter, uniform layer that is extremely resistant to cracks, corrosion, and fatigue. Because of these benefits, the springs and transmission components of almost every automobile are shot peened for longer life, as are aircraft structural components.
With the invention of the laser, researchers quickly recognized that peening could be achieved using high-energy lasers with pulse lengths in the tens of nanoseconds billionths of a second, short enough to generate a rapid yet energetic shock. Prototype laser peening machines were developed in the 1970s, but they and subsequent versions over the past two decades were not cost effective because the lasers lacked the high repetition rate required for treating parts rapidly.”
For the entire article click on this link: Blasts of Light to Strengthen Metals