PROCESSING OF CONTINUOUSLY REINFORCED TI-ALLOY METAL-MATRIX COMPOSITES (MMC) BY MAGNETRON SPUTTERING

The present work deals with a novel vapor synthesis route, the matrix- coated fiber process, for producing SIC fiber reinforced Ti-6Al-4V and Ti3Al-Nb 'orthorhombic' titanium aluminide composites. In this proces s, the matrix alloys were directly deposited on SiC fibers by magnetro n sputtering. The matrix deposition was conducted both as a batch proc ess, wherein short-length fibers were coated with the matrix material using a planar magnetron sputtering system, as well as a continuous pr ocess, in which the matrix was deposited on continuous SiC fibers usin g a reel-to-reel hollow-cathode magnetron sputtering system. The matri x-coated fibers were consolidated to produce unidirectionally reinforc ed composite panels, Unreinforced matrix alloy samples were also fabri cated using the same sputtering and consolidation conditions. Followin g heat treatments, the microstructural evolution in these materials we re studied. Tensile tests at room temperature were also conducted on m atrix and composite specimens. The results indicated that PVD foils an d fiber coatings can be heat-treated to obtain microstructures similar to those obtained via conventional processing approaches. Further, th e room-temperature tensile properties of PVD foils are comparable to c onventionally rolled foils or sheets. (C) 1998 Elsevier Science S.A. A ll rights reserved.