Primary study of the isothermal phase diagram of the Cu 2O-Al 2O 3-SiO 2 ternary system at 1150°C in air

Abstract

The isothermal phase diagram of the Cu 2O-Al 2O 3-SiO 2 ternary system at 1150°C was reported for the samples which were prepared from sol-gel method and quenched by water after being heated at 1150°C for 12 h. Based on the conventional X-ray powder diffraction (XRD) and in situ high-temperature XRD quantitative analysis, in addition to scanning electron microscopy measurement, the phase identification was achieved. Combining the deduction from the component phase diagrams of the binary systems using the phase equilibrium theorem, the primary isothermal phase diagram was plotted over the composition area Cu 2O-mullite-SiO 2. In this area, the approximate composition areas of two two-phase regions and one three-phase region, (L 2 + Cr), (L 2 + M), and (L 1 + L 2 + Tr), were determined. Moreover, the precise composition areas of both of the three-phase regions (L 2 + Cr + M) and (L 2 + M + A) were determined according to the results of conventional and in situ high-temperature XRD quantitative analysis by Rietveld method.