VAPOR-DEPOSITED FUNCTIONALLY GRADIENT MATERIALS

Various methods are used in inhomogeneous functional graded technology to control the constituent elements of a composite material. Functional graded technology includes chemical and physical processes for such control. The vapor deposition method can be used to fabricate a film or a platelike material directly without need of melting or sintering. Furthermore, composition control of dispersion is comparatively easy in the direction perpendicular to the deposition surface. Fabrication of compositional graded materials (so called functionally gradient materials, FGMs) has been attempted using the vapor deposition method. For instance, Ti-TiC and Ti-TiN FGMs have been fabricated using physical vapor deposition (PVD), and SiC-TiC multilayer film and SiC/C FGM has been fabricated using chemical vapor deposition (CVD). In this paper, functional graded technology employing the vapor deposition method is reviewed.