FIBER COATING DEVELOPMENT FOR ALPHA-2 TITANIUM ALUMINIDE COMPOSITES

UNIVERSAL ENERGY SYSTEMS, INC. IS PROPOSING AN SBIR PROGRAM TO DEVELOP COATINGS FOR FIBERS TO BE USED AS REINFORCEMENT IN ALPHA(2)TI(3)AL BASED COMPOSITES. THE REQUISITE ROLE OF THE FIBER COATINGS IN THESE COMPOSITES IS TO MINIMIZE INTERDIFFUSION AND REACTION ZONE FORMATION AND/OR TO PROVIDE REASONABLE RESIDUAL STRESS ACCOMMODATION AT THE FIBER/MATRIX INTERFACE, WHILE MAINTAINING AN EFFECTIVE LOAD TRANSFER BETWEEN THE MATRIX AND THE FIBER. THE SPUTTER DEPOSITION PROCESS IS PROPOSED FOR THE COATING DEPOSITION, PRIMARILY BECAUSE IT OFFERS LOW-TEMPERATURE PROCESSING, EXCELLENT CONTROL IN COATING CHEMISTRY, HOMOGENEITY, AND UNIFORMITY, GOOD REPRODUCIBILITY, HIGHPURITY END-PRODUCTS, AND REALISTIC DEPOSITION RATES, COUPLED WITH EXCELLENT POSSIBILITIES OF COMMERCIALIZATION. THE PHASE I TECHNICAL OBJECTIVE IS TO DEMONSTRATE THE POTENTIAL OF THIS PROCESS FOR OBTAINING HIGHLY CONTROLLED, COMPOSITIONALLY HOMOGENEOUS, UNIFORM COATINGS OF NBC/NB, MO(2)C/MO, AND TIB(X) ALPHA-BASED TITANIUM ALUMINIDE (SUPER ALPHA(2)) COMPOSITES. THE FEASIBILITY OF THIS APPROACH WILL BE ASSESSED THROUGH OPTIMIZATION OF DEPOSITION CONDITIONS AND COATING THICKNESS, EVALUATION OF COATING INTEGRITY, COMPOSITION, AND MORPHOLOGY, AND DETERMINATION OF THE INTERFACIAL STABILITY AND INTERFACIAL STRENGTHS IN THE COMPOSITES.