Formation of Boron Nitride Coating on SiC Fibers by Electrophoretic Deposition Method Using Pulsed Direct Current Field

ABSTRACT To develop a low cost, low environmental, and short‐time boron nitride (BN) coating process on SiC fibers for SiC f /SiC composites, the authors focused on the pulsed direct current (DC) electrophoretic deposition (EPD) method. First, the effects of DC ON/OFF ratio and migration time on the microstructure of BN deposition on the carbon plate substrates were evaluated, and it was demonstrated that uniform BN deposition was formed under the conditions of DC ON/OFF ratio of 1 ms/10 ms and a migration time of 1 min. BN coating with the thickness of 170, 260, and 360 nm was formed on SiC fibers by both continuous and pulsed DC EPD at applied voltage of 5, 10, and 20 V and migration time of 1 min, respectively. The present study demonstrated that comparable BN coating to the continuous DC EPD was successfully formed under the application of higher voltage in a short time by pulsed DC EPD.