The CVI-Process : State of the Art and Perspective

Chemical vapor infiltration (CVI) is used to produce ceramic matrix composites starting from a multidirectional fiber preform and gaseous precursors of the constituents. The fundamentals of the process in terms of preform pore network, transport phenomena, chemistry, nature of the deposit and gaseous reaction by-products, are depicted. The advantages and drawbacks of the basic version of CVI (I-CVI) are presented and briefly discussed. Related versions, designed to increase the deposition rate and shorten the densification time (TG-CVIi F-CVI, LV-CVI) or to tailor the interphase and matrix microstructure (P-CVI), are comparatively discussed. Finally, new developments and perspectives are presented.