FORMATION OF BORON-NITRIDE THIN-FILMS ON BETA-SI3N4 WHISKERS AND ALPHA-SIC PLATELETS BY DIP-COATING

Thin films of boron nitride have been deposited on the surface of beta -Si3N4 whiskers and alpha-SiC platelets by dip-coating in aqueous and methanolic boric acid solutions, respectively followed by drying at ro om temperature, heating in nitrogen flow, and finally nitriding in an ammonia flow at 1000 degrees C. X-ray photoelectron spectroscopy (XPS) , infrared (IR) spectroscopy and scanning electron microscopy (SEM) st udies proved the formation of boron nitride surface coating. The XPS s tudies indicated that the methanolic boric acid solution was a more ef fective precursor as compared to the aqueous solution. Transformation of H3BO3 to BN was much more efficient on the surface of SiC platelets than on that of Si3N4 whiskers. (C) 1998 Elsevier Science Limited. Al l rights reserved.