Moessbauer effect spectroscopic studies were made on Na-FeSi02 glasses before and after wetting experiments on steel in an Ar atmosphere. The glasses prepared under reducing conditions contained Fe3+ ions. The Fez+/Feq+ ratio for all glasses increased a5 the time at wettability test temperature was increased. Iron in the glasses (according to isomer-shift data) was possibly octahedrally coordinated. The Fe environment in glasses very nearly saturated with Fe oxide was most symmetrical. The glasses prepared under reducing conditions exhibited more symmetrical Fe environments than those prepared under oxidizing conditions. The structural symmetry in the glasses very nearly saturated with Fe oxide facilitated the electron transfer reaction, 2Fe"++ Feo= 3Fep+; the conversion to Fez+ occurred to the greatest extent in these glasses.

Gläser des Systems Na2O‐Fe2O3(FeO)‐SiO2 wurden vor und nach Benetzungsversuchen an Stahl in Ar‐Atmosphäre Mössbauer‐spektroskopisch untersucht, um die Koordination von F e in den Adnäsionsscnicnten zu oesummen.

Wetting behavior of molten NaJ%Fe203-SiOz and Na,O-FeO-SiO, glasses on very-low-carbon steel a t 900°C in purified Ar was studied. The steel surface was dry-polished and cleaned by ion bombardment. Glass frit was then placed on the metal, and the system was introduced into the furnace without exposure to air. Dynamic advancing and receding contact angles were measured. Shear (push-off) tests were performed on the glasssteel composite a t room temperature to determine adherence. The equilibrium contact angles were obtained from the arithmetic mean of the final advancing and receding angles. As the Fe oxide content of the glasses increased, the degree of wetting improved; Fe3+ was more effective than a combination of Fe3+ and Fe2+ in improving the wettability. Glasses very nearly saturated with Fe oxide exhibited high adherence values and chemically adhered to steel.

Das Benetzungsverhalten geschmolzener Na2O‐Fe2O3‐ SiOz‐ und Na2O‐FeO‐SiO2‐ Gläser auf wenig Kohlenstoff enthaltendem Stahl bei 900°C wird in gereinigtem Ar untersucht.

No abstract