Fabrication of SiCf/Ti3SiC2 by the electrophoresis of highly dispersed Ti3SiC2 powder

This paper reports the processing details and important phenomena occurred during the fabrication of a SiC fiber-reinforced Ti3SiC2 matrix composite (SiCf/Ti3SiC2). Because both SiC and Ti3SiC2 are microwave absorbing materials, the fabrication of SiCf/Ti3SiC2 deserves extensive study, where an improved mechanical property is expected due to the SiC fibers incorporated in the Ti3SiC2 matrix. To fabricate the composite, a highly dispersed Ti3SiC2 slurry was prepared by considering both steric and electrostatic dispersion mechanisms after adding different types of dispersants and polymeric processing additives. Electrophoresis was performed under a DC electric field to infiltrate the Ti3SiC2 particles into the voids of Tyranno (TM)-SA grade 3 woven fabric, followed by hot pressing at 1350 degrees C under 20 MPa. High energy milling of the starting material accelerated the decomposition of Ti3SiC2 during sintering due to mechano-chemical activation. By adopting mild ball milling, however, SiCf/Ti3SiC2 with a density >= 90% and a flexural strength >= 100 MPa could be fabricated, retaining the most of Ti3SiC2 matrix phase.