Experimental evaluation of chemical resistance of steatite products towards aluminum-based melts

The processes taking place with a spray unit during aluminum dispersion have been analyzed. It has been shown that the major process which occurs in a nipple during aluminum flowing is the reduction of silicon with aluminum and, also, with magnesium from the melt (in case when aluminum-magnesium or magnesium-containing alloys are used). The reduction of silicon results in the formation of nanoscale particles with crystalline size 20–50 nm and leads to the degradation of the nipple material, which is accompanied by its cracking and the formation of nanoscale channels and the flow of melt into the material through these channels. This phenomenon leads to the rupture and/or blockage of the nipple.