THE UTILIZATION OF GRAPHITE/ALUMINUM (GR/AL) COMPOSITES IN ENGINEERINGSTRUCTURES HAS BEEN SEVERELY LIMITED BY LOW TRANSVERSE TENSILE STRENGTH.

THE UTILIZATION OF GRAPHITE/ALUMINUM (GR/AL) COMPOSITES IN ENGINEERINGSTRUCTURES HAS BEEN SEVERELY LIMITED BY LOW TRANSVERSE TENSILE STRENGTH. HOWEVER, RECENT DEVELOPMENTS IN THE MANUFACTURE OF METAL MATRIX COMPOSITE BY PHYSICAL VAPOR DEPOSITION TECHNIQUES HAVE RESULTEDIN THIN-SHEET GR/AL COMPOSITES HAVING TRANSVERSE TENSILE STRENGTHS OF 70-110 MPA (10-16KSI), WHICH WAS ATTRIBUTED TO IMPROVED FIBER/MATRIX BONDING. BETTER DEFINITION OF BOND QUALITY WILL BE OBTAINED IN THIS PROGRAM BY PRODUCING CONTINUOUS ION-PLATED GR/AL COMPOSITE PRECURSOR TAPES WITH A WELL-DEFINED CARBON INTERPHASE INTRODUCED BETWEEN THE FIBERS AND MATRIX SUCH THAT ITS EFFECT ON TRANSVERSE TENSILE STRENGTH IS CLARIFIED. THIS CARBON COATING IS DEPOSITED DIRECTLY ON EACH CARBON FIBER BY A PLASMA-ENHANCED CHEMICAL VAPOR DEPOSITION PROCESS, THE PARAMETERS OF WHICH CONTROL THE MECHANICAL PROPERTIES OF THE INTERPHASE. CONCURRENTLY, A FINITE ELEMENT MICROMECHANICAL ANALYSIS OF THE COMPOSITE WILL BE DEVELOPED WHICH INCORPORATES THE INTERPHASE EFFECTS AND PREDICTS MACROSCOPIC BEHAVIOR OF THE COMPOSITE. FOUR INTERPHASE COATINGS WILL BE PRODUCED. MECHANICAL PROPERTIES OF THE CONSOLIDATED COMPOSITES WILL BE COMPARED TO THEORETICAL PREDICTIONS OF THE MODEL AND AN OPTIMIZATION PROGRAM WILL BE FORMULATED.