Experimental liquidus studies of the Pb-Fe-Si-O system in equilibrium with metallic Pb

Phase equilibria of the Pb-Fe-Si-O system have been investigated at 943 K to 1773 K (670\ua0°C to 1500\ua0°C) for oxide liquid in equilibrium with liquid Pb metal and solid oxide phases: (a) quartz, tridymite, or cristobalite; (b) (fayalite\ua0+\ua0tridymite) or (fayalite\ua0+\ua0spinel); (c) spinel (FeO); (d) complex lead-iron silicates (melanotekite PbO·FeO·SiO, barysilite 8PbO·FeO·6SiO, 5PbO·FeO·SiO, and 6PbO·FeO·SiO); (e) lead silicates (PbSiO, PbSiO); (f) lead ferrites (magnetoplumbite PbFeO solid solution range); and (g) lead oxide (PbO, massicot). High-temperature equilibration on primary phase or iridium substrates, followed by quenching and direct measurement of Pb, Fe, and Si concentrations in the phases with the electron probe X-ray microanalysis, has been used to accurately characterize the system in equilibrium with Pb metal. All results are projected onto the PbO-“FeO”-SiO plane for presentation purposes. The present study is the first systematic characterization of liquidus over a wide range of compositions in this system in equilibrium with metallic Pb