Silicon carbide, with single‐edge precracked beam (SEPB) toughness greater than 7 MPa·m1/2, was made by hot‐pressing using Al–B–C (ABC) or Al–Y2O3 (YAG) as additives. The hardness of SiC processed with a liquid phase was always less than SiC densified without a liquid phase despite having a similar or finer grain size. With increasing Al content, the ABC system changed from trans‐ to intergranular fracture with a drop in hardness and a two‐ to threefold increase in SEPB toughness. Strength and Weibull modulus for materials processed with a liquid phase were higher than those of solid‐state densified SiC. Ballistic testing, however, did not show any improvement over SiC densified with B and C additives. Depth of penetration was controlled by hardness of the SiC‐based materials, while V50 values for 14.5 mm WC–Co cored projectiles were in the range of 720–750 m/s for all materials tested.

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The term “microfabrication” has been used primarily as an acronym for silicon-based device fabrication. Recent developments in ceramic processing technology have resulted in cost-effective, scalable options of ceramic microfabrication that offer the potential for fabrication of devices with a number of advantages over silicon-based microdevices for specific applications. These advantages include the ability to fabricate devices with three-dimensional architecture, high-temperature operation up to 1200°C, porous layers for gas diffusion, and textured substrate properties for specific applications through wider materials selection. Processing routes for these ceramic microdevices with three-dimensional architecture include established processes such as tape casting, laser machining, lamination and sintering, or new processes such as reaction bonding and lost-mold techniques. The ability to fabricate three-dimensional feature geometries allows the application of these ceramic microfabrication techniques for device fabrication targeted at a number of applications such as point-of-use high purity gas generation, microchannel devices, microreactors, fiber-optic connectors and heat-pipes for microelectronics.

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