NOVEL ACOUSTIC DAMPING MATERIALS

IMPROVED MATERIALS HAVING A HIGH DAMPING CAPACITY, COMBINED WITH GOOD MECHANICAL PROPERTIES AND SUITABLE FOR STRUCTURAL USES, ARE NEEDED IN A VARIETY OF APPLICATIONS. AMONG THE AREAS IN WHICH ACOUSTIC DAMPING IS DESIRABLE ARE IMPROVING THE RESPONSE AND ACCURACY OF TRACKING, POINTING, AND GUIDANCE SYSTEMS; INCREASING "STEALTH", AS WELL AS PERSONNEL COMFORT; AND ISOLATING AND/OR PROTECTING SENSITIVE EQUIPMENT. IN THIS PHASE I PROGRAM, ULTRAMET PROPOSES TO DEVELOP AND INVESTIGATE THE POTENTIAL OF A UNIQUE NEW CLASS OF MATERIALS HAVING CONTINUOUS CERAMIC AND METAL MATRICES, FABRICATED BY INFILTRATING A METAL MATRIX INTO A RETICULATED, HIGH-MODULUS CERAMIC FOAM BY CHEMICAL VAPOR INFILTRATION (CVI), A VARIATION OF THE CHEMICAL VAPOR DEPOSITION (CVD) PROCESS. THIS INNOVATIVE MATERIAL WILL POSSES THREE-DIMENSIONAL INTERCONNECTED MATRICES OF BOTH CERAMIC AND METAL PHASES, OFFERING THE MODULUS AND DIMENSIONAL STABILITY OF A CERAMIC WITH THE FRACTURE TOUGHNESS AND FABRICABILITY OF A METAL. ADDITIONALLY, THE VAST DIFFERENCE IN ELASTIC MODULI BETWEEN THE TWO PHASES WILL PROVIDE SIGNIFICANT ACOUSTIC DAMPING CAPACITY, PARTICULARLY SUITED FOR LOW-FREQUENCY ATTENUATION. THIS STIFF, STRONG CERAMIC/METAL MATRIX COMPOSITE WILL REPRESENT A SIGNIFICANT ADVANCE OVER CURRENT TECHNOLOGY.