Using pyrolytic carbon-coated short carbon fiber to fabricate Csf/ZrB2-SiC composites by direct ink writing and precursor infiltration pyrolysis

Abstract

Direct ink writing (DIW) offers significant advantages for efficient manufacturing of complex ceramic composite components. However, the mechanical properties of short carbon fiber-reinforced ceramic composites fabricated by DIW technology were not ideal, mainly be ascribed to the absence of a suitable coating on the fiber as an interface. In this work, Csf/ZrB2 green bodies were printed by an optimized extrusion process using pyrolytic carbon-coated short carbon fibers (Csf). High-performance Csf/ZrB2-SiC composites were obtained through the infiltration and pyrolysis of SiC precursor six times. With increasing Csf content, the dimensional deviations decreased and the mechanical properties increased. When the Csf content was 30 vol.%, the dimensional deviation of the Csf/ZrB2-SiC composite was less than −0.5% in the X and Y directions and about −2% in the Z direction. A marked increase in the flexural strength and fracture toughness of the composite was also obtained, reaching 275.0 MPa and 5.26 MPa·m1/2, respectively.