A SEM EDXA STUDY ON THE CHEMICAL ATTACK OF AQUEOUS NAOH/KOH SOLUTIONSON THE SURFACE OF THE METAL-METALLOID GLASS (FE,CR)(80) (P,C,SI)(20) AND FE75CR5P8C10SI2, RESPECTIVELY/

After a treatment of the metal-metalloid glassy alloy (Fe, Cr)(80)(P, C, Si)(20) and Fe75Cr5P8C10Si2, respectively, by aqueous alkaline solu tions of 1.0 M NaOH + 1.0 M KOH and 2.5 M NaOH + 2.5 M KOH, respective ly, a SEM/EDXA study of the glass surface was performed. The results o f the accelerated ageing procedure demonstrate that the glass treated with the 1.0 M NaOH + 1.01 M KOH solution at room temperature (20 degr ees C) is characterized by a surface state like that of the initial ma terial. For the glass treatment with the 2.5 M NaOH + 2.5 M KOH soluti on at 20 degrees C the surface layer shows a different morphology and is thicker. It can be supposed that the reinforcing property is reduce d. The glass treatment at 80 degrees C with the aqueous solutions 1.0 M and 2.5 M (NaOH + KOH), respectively, leads to surface layers of dif ferent morphology and such a layer is about 5 mu m thick. The strength of solid residue of such a treated glass is very low.