Fabrication of a 3D4d braided SiCf/SiC composite via PIP process assisted with an EPD method

Abstract

Abstract In order to improve the thermal conductivity and full-fill the gaps between the fiber bundles for three-dimensional four-directional (3D4d) braided SiCf/SiC composites, 500 nm submicron-sized β-SiC particles were introduced into the 3D4d preform by an electrophoretic deposition (EPD) method. ζ-potential of the KD-Ⅱ SiC fibers and the aqueous suspension of the β-SiC particles were analyzed, as well as the efficiency of the deposition. After densified via PIP process, microstructure, three-point bending strength and thermal conductivity of the composite were investigated. The results showed that, SiC particles filled the gaps between the SiC fiber bundles efficiently, and thermal conductivity of the composites fabricated through PIP process assisted by EPD was 2.3 times that of the composites fabricated via PIP only. The bending strength of the EPD-composites was 647.08 ± 69.53 MPa, which decreased to 2/3 of that of the composites manufactured only by PIP, owing to the reduction of fiber volume fraction and the damages to the interface coatings and fibers under the action of the electric field.