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MgO-”FeO”-SiO 2 FeO and MgO showing a solid soln. Fig. 6.59. System MgO-”FeO”-SiO 2 including binary systems.
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MgO-”FeO”-SiO2 • FeO and MgO showing • a solid soln Fig. 6.59. System MgO-”FeO”-SiO2 including binary systems.
Fig. 6.57. System MgO-”FeO”-SiO2 (oxide phases in equilibrium with metallic iron) (after E. F. Osborn and A. Muan, Phase Equilibrium Diagrams of Oxide Systems. American Ceramic Society, Columbus, Ohio, 1960).
1800°C O+L Magnesiowustite +Forsterite-Fayalite(Olivine) M+O M+L SiO2 2900°C 2700°C 2000°C L L MgO FeO L+M M L+M Magnesiowustite 1870°C 1860°C solid solubility
T T T decrease P P L O+L O two pts meet at 1543°C 1550°C 1527°C X+L X+P X+L P+L P+L O+P O+P O+L O+L M+O M+O M+L M+L pyroxene (P) is (MgO,FeO)SiO2 cristobalite (X) transformed to tridymite (T) at 1470oC 1450°C T+L P+T T+P+L and O+P+L meet at 1305°C, and P+L disappears P+L O+P O+L M+O M+L
the relation between the structure of a ternary diffusion couple and the phase diagram