FABRICATION OF SiCf/SiC–ZrB2 COMPOSITES BY A HYBRID PROCESS OF ALTERNATING CURRENT ELECTROPHORETIC DEPOSITION (AC-EPD) AND HOT PRESSING
October 1-6, 2017
In this study, we report on the fabrication of continuous SiC fiber-reinforced SiC–ZrB2 ceramic matrix composites (SiCf/SiC–ZrB2) through a hybrid process of slurry impregnation by electrophoretic deposition and hot pressing. An effective impregnation of the slurry into the fine voids of fiber preform is essential to fabricate dense composites, which was achieved by a simple, fast and efficient electrophoretic deposition method. With increased interest in ultra-high temperature ceramics (UHTCs), there has been a significant effort on the development of SiC–ZrB2 composites. Numerous efforts have been also made on the incorporating of fiber reinforcement phase into these UHTCs to enhance overall mechanical properties in recent years. In this regard, SiCf/SiC–ZrB2 composites were fabricated by infiltrating a SiC–ZrB2 matrix phase containing Sc2O3 sintering aid into the TyrannoTM-SA grade-3 fabrics coated with pyrolytic carbon and SiC interphase layers using an AC electrophoretic deposition (AC-EPD) combined with ultrasonication. AC-EPD was performed using a dual electrode system under an applied voltage of 20 V for 30 min. The zeta potential of the slurry was set to ≥ +40 mV at pH = 10 to achieve uniform infiltration of constituent particles into the preform. After infiltrating water-based slurry into the fine voids of fabrics by AC-EPD, 15 layers of fabrics were stacked and laminated. Hot pressing was carried out at 1750oC in an Ar atmosphere after binder burnout. The composite densities, microstructures and mechanical properties as a function of the various processing parameters along with the effectiveness of AC-EPD will be discussed in detail.
Kati Raju, Wahid Muhamad, Dang-Hyok Yoon, and Seyoung Kim, "FABRICATION OF SiCf/SiC–ZrB2 COMPOSITES BY A HYBRID PROCESS OF ALTERNATING CURRENT ELECTROPHORETIC DEPOSITION (AC-EPD) AND HOT PRESSING" in "Electrophoretic Deposition VI: Fundamentals and Applications", Aldo R. Boccaccini, Institute of Biomaterials, University of Erlangen-Nuremberg, Germany Omer van der Biest, Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Belgium James Dickerson, Consumer Reports, USA Tetsuo Uchikoshi, National Institute for Materials Science, Japan Eds, ECI Symposium Series, (2017). http://dc.engconfintl.org/electrophoretic_vi/16