Gas Turbine Blade Quality Inspection

High pressure turbine blades operate in the harshest environments and are subjected to extreme temperatures.  Because these gas turbine blades are critical components of gas turbine engines, and because of the conditions they are subject to throughout their lifespan, they are subject to intense testing and inspection both at manufacture and at scheduled maintenance and engine service repair intervals. Traditionally, initial quality inspections rely heavily on visual inspection. In addition, other non-destructive methods are used: fluorescent liquid penetrant for exterior surfaces, radiography for the interior structure, ultrasonic inspection to verify wall thicknesses, and Laue x-ray diffraction for the single crystal grain structure. Whether gas turbine blade inspection is taking place at the time of manufacture or during repair at a maintenance, repair, and overhaul (MRO) service facility, utilizing Non-Destructive Testing Resonant Acoustic Method (NDT-RAM) provides additional benefits not available from other testing types.

Why add NDT-RAM to the Gas Turbine Blade Inspection Process?

Adding NDT-RAM inspections to the post-manufacture or post-repair inspection process for gas turbine high pressure turbine blades adds an additional measure of safety. NDT-RAM 

• Is more sensitive to certain blade defects than current testing methods
• Is structural-based – find structural flaws, metallurgical issues, and blind defects not otherwise detected
• Is non-destructive (test all blades instead of a representative blade)
• Provides straightforward pass/fail results
• Use statistical data to help detect material aging
• Retains data for further statistical analysis to understand mold to mold, batch to batch, and other variations over time
  • Incoming material integrity
  • Heat treatment batch variation
  • Vendor consistency

Download the White Paper Gas Turbine Blade Quality Inspection to learn more.