STUDY OF THE INTERACTION BETWEEN LIQUID ALUMINUM AND SILICON-NITRIDE

The sessile drop method was used to determine the evolution as a function of time and temperature, under vacuum, of the contact angle theta of molten aluminum on two kinds of silicon nitride (SRBSN and CVD-SN). These results are discussed in terms of thermodynamic calculations (stability of a superficial metal oxide layer) coupled with morphological observations and characterization of the ceramic/metal interface. The limited interfacial corrosion and the formation of a protective dense aluminum nitride layer lead to the conclusion that silicon nitride is a good candidate as a corrosion resistant material for the handling or the melting of liquid aluminum.