|Technology Improves Jet Engine Readiness |
Technology Improves Jet Engine Readiness
By Mike Griffin, Air Force Research Laboratory.
Dublin, Ohio -- March 5, 2001 (AFPN) -- The Air Force has a new weapon in the battle against foreign object damage -- a laser that strengthens engine fan blades and rotors.
Otha Davenport, director of engineering for Aeronautical System Center's Propulsion Product Group, checks the results of a laser shock peening strengthening process on an F-119 engine's bladed rotor at LSP Technologies in Dublin, Ohio. An LSP employee assists. (Courtesy photo)
Called "laser shock peening," this technology uses high-powered lasers to "cure" aircraft engine parts. This makes them stronger and better able to resist foreign objects that causes millions of dollars in damaged aircraft engine parts each year.
LSP Technologies Inc., of Dublin, developed the technology through the Air Force Research Laboratory's manufacturing technology program, known as ManTech.
During the "curing" process, a laser is repeatedly fired along the edges of the blades. The shock wave caused when the laser beam strikes the blade's surface actually compresses the metal, toughening the blade. This process increases blade damage tolerance by as much as 15 times normal strength, according to program officials.
"By (using) new technologies, such as laser shock peening, to make Air Force systems more reliable, affordable and maintainable, ManTech is helping the warfighter," said Dan McDermott, chief of the directorate's manufacturing technology division. The new method replaces a former process called shot peening, where metal or glass beads were fired at blade edges, McDermott said.
"This original process was good, but the new laser approach is better because it drives the shock waves deeper into the metal, producing engine blades that are more resistant to failure or foreign object damage," he said. "This translates into a major increase in warfighting capability for the Air Force."
Using laser shock peening, it takes about 30 minutes to process one blade on the F-110 engine used in the Air Force's F-15E Strike Eagle and F-16C and D Fighting Falcon fighter aircraft. Under the ManTech program, LSP Technologies has developed an automated process using robotics that eliminates handling the blades manually during the peening process, according to McDermott.
Called Rapid Coater, this new approach reduces peening time from 30 to 12 minutes.
"In time, we anticipate reducing that to four minutes per blade, using a newer, faster laser dubbed Rapid Peen," said David W. See, LSP directorate program manager. "Laser shock peening, more economical than the old method, is increasing throughput by nine times over previous, manual peening activities. In fact, we've just kicked off a new contract to laser peen integrally bladed rotors from the F-119 engine used in the F-22 Raptor."
"Since we implemented laser shock peening processes, I can't think of a time when we've lost an engine due to high-cycle fatigue of laser-peened fan blades," said Otha Davenport, director of engineering for Aeronautical Systems Center's propulsion product group. "Laser shock peening allows us to peen areas of the blades other peening processes cannot reach. For example, there are probably half-a-dozen places alone where laser shock peening can be used to increase durability of the F-119 engine." (Courtesy of Air Force Material Command News Service)
- Air Force Research Laboratory