AN IMPROVED METHOD OF HOLOGRAPHIC NONDESTRUCTIVE INSPECTION OF METAL MATRIX COMPOSITES FOR GAS TURBINE ENGINES

THE AIM OF THIS PROJECT IS TO DETERMINE THE FEASIBILITY OF A NOVEL, REAL TIME, HOLOGRAPHIC INTERFEROMETRIC TECHNIQUE IN THE SUBSURFACE INSPECTION OF METAL MATRIX COMPOSITE PARTS IN GAS TURBINE ENGINES. THE INTENT IS TO USE COMMON PATH, PHASE SHIFT TECHNIQUES TO ENHANCE THE SENSITIVITY OF HOLOGRAPHIC INTERFEROMETRY TO FLAW DETECTION AND BOND CHARACTERIZATION, WHILE AT THE SAME TIME, MINIMIZING THE INFLUENCE OF THE TECHNIQUE ON HEALTHY, WELL-FORMED AREAS. A THERMOPLASTIC CAMERA WILL BE USED TO RECORD THE HOLOGRAMS, SINCE IT IS CAPABLE OF IN SITU DEVELOPMENT AND LATER ERASURE FOR REUSE. SPECIMENS OF TITANIUM ALUMINIDE MATERIAL WILL BE OBTAINED, BOTH HEALTHY, AND WITH PROGRAMMED DEFECTS, AND A COMPARISON WILL BE MADE OF THE TWO TYPES OF RESULTING INTERFEROGRAMS. THE OUTCOME OF THE PHASE I RESEARCH EFFORT WILL BE AN ASSESSMENT OF THE TECHNIQUE IN LOCATING FLAWS IN THE COMPOSITE MATERIALS, AND A SET OF DEFINED RECOMMENDATIONS FOR THE DEVELOPMENT IN PHASE II OF AN AUTOMATED VERSION OF THE DEVICE FOR COMMERCIAL APPLICATION. THE LONG-TERM OBJECTIVE OF EOCS IS THE COMMERCIALIZATION OF THIS DEVICE FOR USE IN THE MILITARY AND AEROSPACE INDUSTRIES.