Wettability of ceramics with molten silicon at temperatures ranging from 1693 to 1773 K

Wettability of ceramics with molten silicon have been determined with a ses sile drop method. The contact angles between molten silicon and the oxide p lates, such as SiO2(s), Al2O3(s), MgO(s) are in the range from 85 degrees t o 88 degrees. Contact angle between SiO2(s) and Si(l) was further investiga ted from the meniscus shape of molten silicon in the vicinity of SiO2(s)Si( l)-gas three phases boundary. The contact angle is 87 degrees and close to the results obtained by the sessile drop method. At the interface between S i(l) and the BN substrate, a discontinuous Si3N4 layer Is expected to form and the layer may prevent BN from dissolving into molten silicon. The BN su bstrate has large contact angle (around 145 degrees) with molten silicon an d the contamination by the BN substrate is so insignificant that the BN pla te is regarded as the most suitable substrate for supporting a silicon drop in the surface tension measurement. Contact angle between molten silicon a nd BN decreases with increasing P-O2 in argon atmosphere. Contact angle bet ween molten silicon and Si3N4 is about 90 degrees. Molten silicon spreads o ver the SiC plate anti the contact angle was estimated to be 8 degrees.