Electrochemical characterization of glass/Al reactions at high temperature

A high temperature Al(−)/glass/stainless steel–O2(+) system, was studied and characterized by SEM and EDS analysis. Indeed, a potential ranging from 1.75 to 1.5 V between steel and aluminum, at a temperature above 500 °C, has been observed. By connecting this package to a resistance, a current flow was detected. Above the aluminum melting point, there is a reaction between SiO2 glass and metal, with formation of Al2O3 and Si, moreover there is a change in the soda-lime glass composition, a nucleation of crystalline phases in the glass itself, and the formation of a porous layer of alumina, with the typical inhomogeneity of a system heated at this temperature. It seems that the current passing through the glass phase, by the electric field generated by the formation of a metal/air cell, can influence the composition of the glass phase at high temperature and can inhibit the nucleation and the growth of crystalline zones.