Fabrication of Metal Matrix Composites by Physical Vapor Deposition of Matrix Material on Ceramic Fibers

UES is proposing a novel vapor synthesis route for producing MMCs in which the matrix alloy will be directly deposited on reinforcing fibers by magnetron sputtering under UHV conditions. A post-deposition consolidation will be used to fabricate MMC's directly from the matrix-containing fibers. This fabrication route offers the following advantages: (a) a very clean environment with excellent impurity control, (b) good repeatability/reproducibility, (c) control of matrix volume fraction, primarily through control of matrix coating thickness, (d) control over chemistry and homogeneity of the deposited matrix, (e) uniform fiber distribution, (f) lower processing temperatures, and (g) flexibility in fiber-matrix interface control/design. The specific objectives of the Phase I effort are: (1) to demonstrate the potential of the sputter deposition process for obtaining highly controlled, uniform, adherent deposits of the titanium aluminide alloy, Ti-22Al-23Nb, on short-length SiC fibers, (2) to demonstrate the feasibility of obtaining MMC's by consolidation of the matrix-containing fibers, (3) to demonstrate proof-of-concept through microstructural studies, thermal cycling and room temperature tensile tests on the fabricated MMC's, (4) to develop a conceptual and engineering design of a reel-to-reel coating system for deposition of matrix alloys on continuous fibers, and (5) provide a comparative cost analysis of the proposed technique in relation to conventional MMC manufacturing processes.