A NUMBER OF TECHNOLOGIES HAVE BEEN IDENTIFIED AS CRITICAL TOACHIEVING THE OBJECTIVES OF THE ADVANCED ROTARY COMBINATION ENGINE PROGRAM.

A NUMBER OF TECHNOLOGIES HAVE BEEN IDENTIFIED AS CRITICAL TOACHIEVING THE OBJECTIVES OF THE ADVANCED ROTARY COMBINATION ENGINE PROGRAM. AMONG THESE ARE A HIGHER HOT STRENGTH ALUMINUM ALLOY, A LIGHT-WEIGHT ROTOR, AND ALTERNATE APEX SEAL/TROCHOID COATING MATERIALS. A NEW METAL MATRIX COMPOSITE, A CAST SILICON CARBIDE/ALUMINUM WHICH IS FABRICATED UTILIZING CONVENTIONAL FOUNDRY PROCESSES, HAS MANY CHARACTERISTICS THAT MAKE IT A DESIRABLE MATERIALS CANDIDATE FOR THE ABOVE-MENTIONED APPLICATIONS. RELATIVE TO THE BASE ALUMINUM ALLOY, SPECIFICSTIFFNESS AND SPECIFIC STRENGTH INCREASES OF 70 PERCENT AND 30 PERCENT, RESPECTIVELY, CAN BE OBTAINED. AN OPERATIONS TEMPERATURE OF 550 DEGREES F MAY BE POSSIBLE. FATIGUE RESISTANCE IS EQUIVALENT TO STAINLESS STEEL AND WEAR RESISTANCE IS ENHANCED. THERMAL EXPANSION IS REDUCED WHICH SHOULD INCREASE COMPATIBILITY WITH HOUSING COATINGS. A PRELIMINARY MECHANICAL AND THERMAL PROPERTIES TEST PROGRAMWILL BE CONDUCTED ON SIC/AL COMPOSITES, UTILIZING CASTING ALLOYS OF INTEREST TO THE ROTARY ENGINE PROGRAM. AN EVALUATION WILL BE MAKE OF POSSIBLE ROTARY ENGINE COMPONENT APPLICATIONS AND COMPARED WITH BASELINE MATERIALS. A STUDY OF THE COMPATIBILITY OF IMPROVED COATINGS WITH THE SIC/AL MATERIAL WILL ALSO BE CONDUCTED.