A Comparison of Various Non-Destructive Inspection Processes Using Hot Isostatically Pressed Powder Turbine Parts.

摘要

Four emerging NDE (non destructive evaluation) processes were explored using aircraft turbine rotating hardware or simulated samples as test specimens. The material was a high strength nickel-base alloy, Rene' 95, which was made by hot isostatically pressing powder. The bases of comparison were conventional FPI (fluorescent penetrant inspection) and conventional ultrasonic testing. Neutron radiography and radiographic tomography appear to have insufficient capabilities for NDE of this type of turbine hardware. Conversely, acoustical holography and photon scattering (Compton) methods offer much promise. Both are readily adaptable to fully automatic inspection of hardware. Both appear cost effective based on projected production inspection costs. Both make it possible to reduce metal envelopes of raw material thus decreasing material costs. The acoustical holography process represents a later stage of development than the photon scattering method but both processes require additional development effort to obtain a production process. Much of this effort is in computer hardware and software which would reduce inspection time and permit calibration of equipment. Results of inspection scans of test specimens are presented and compared to this report. Specific recommendations for continued effort is also outlined. (Author)