| Abstract Scope |
Advanced/additive manufacturing (AM) techniques and densification processes relevant to fabricating ceramic matrix composites (CMCs) are surveyed. Current and potential future AM techniques are considered, including those applied to create both short and continuous fiber CMCs. Techniques to generate short fiber preforms, such as extrusion/direct ink write (DIW), binder jet (BJP), digital light processing (DLP) are elucidated. Advanced printing technologies that can deliver continuous fiber preforms are considered including systems employing X-Y-Z gantry structures, filament winding and 3D robotic printing of continuous fiber and resin. Once AM preform fabrication is complete, densification is performed. For most CMCs, net-shape densification is necessary to avoid bucking of the fibers that would occur during sintering shrinkage. The three primary densification processes will be reviewed, including reactive melt infiltration (RMI), polymer infiltration and pyrolysis (PIP), and chemical vapor infiltration (CVI), with advantages and disadvantages being discussed. Combining densification techniques will also be discussed. |