The manufacturers of industrial gas turbine engines have long relied upon various nondestructive testing (NDT) techniques, including X-ray and ultrasound, to ensure the quality of their turbine blades. But Alstom Power's Industrial Gas Turbines facility (Lincoln, UK) -- which makes turbines used in the aerospace, marine and power generation industries -- was in search of a better way.
One key characteristic of turbine blade quality involves the internal cooling passages formed in each blade so that air can pass through. Because the hundreds of blades used in each engine are subjected to high operating temperatures, a defect in any of the cooling features can cause overheating of the blade, ultimately resulting in blade failure and an unplanned engine shutdown. Failure of any sort requires tear down and repair, accompanied by out-of-service delays and costs.