Not the usual laser inquiry
Last summer, PRC Laser received a rather unusual inquiry from Chromalloy Gas Turbine Corp.
Landing, NJ - Last summer, PRC Laser received a rather unusual inquiry from Chromalloy Gas Turbine Corp. One of its project engineers was looking for a laser to match, in his words, the “terrible, ugly, awful” beam quality of the company’s 20-year-old transverse-flow CO2 laser.
Chromalloy Gas Turbine Corp. is a pioneer in high-temperature coating of jet aircraft engine vanes and blades. In 1951 it developed a high-temperature diffusion coating to provide oxidation protection on nozzle guide vanes. From the first generation of commercial airliners to today’s supersonic military aircraft this company has led the way with the most advanced coating technologies in the industry. Over the years it developed F.A.A.-approved repair workscopes for dozens of vanes and blades, and these cutting-edge production and repair processes are carried out in its facilities located around the world. Applications include laser cladding and welding of high-strength metal alloys, in addition to a number of other thermal coating processes. With lasers in operation all around the world, Chromalloy has substantial in-house laser expertise.
The Arizona facility had four lasers on the production floor, including one older CO2 laser circa 1980, an Nd:YAG laser, and two modern CO2 lasers. The 20-year-old CO2 laser was great for cladding but had painfully high operating and maintenance costs, while the newer, more reliable units couldn’t clad nearly as well. Their higher beam qualities actually prevented them from achieving the same big spot size and uniform power distribution.
While considering but not favoring the idea of another old CO2 laser from the used market, Chromalloy contacted PRC. The Chromalloy project engineer explained what the company was looking for and why it had to have special beam characteristics. PRC was quickly able to develop a custom optical configuration that would provide an M2 of 4.2 with a flat and even power distribution. After testing and beam analysis at PRC, Chromalloy ordered a new 3.3-kW laser.
A visit to this customer after the installation found four lasers in operation and one sitting on a skid. But it came as a shock to see which laser remained in production right next to the new PRC, none other than the 20-year-old laser that had been challenged, while ironically a one-year-old CO2 laser sat nearby on a skid. Lesson learned: flexibility is key to staying in business. Dick Elam, Chromalloy Arizona project engineer, reported that “this laser is a pussycat, and we’re putting down some beautiful weld beads all the way up to full power” without overheating any of the base metal.
After all the time spent perfecting the beam quality on the STS series lasers to achieve nearly perfect Gaussian beams for welding applications, this project reminds us how important design flexibility is and also why the CO2 laser has such a long and successful track record. Contact Dan Robinson at PRC (firstname.lastname@example.org) to learn more about CO2 laser flexibility.