| Description |
92 leaves in various foliations : illustrations ; 29 cm |
| Summary |
"The effect of oxygen activity on the sintering of Cr₂O₃ with minor additions of MgO, and of MgO with minor additions of Cr₂O₃ at 1600°C was investigated. A peak density (99.4% of theoretical) was obtained for high purity Cr₂O₃ by maintaining the equilibrium oxygen partial pressure needed to maintain the Cr₂O₃ phase. The addition of 0.1 wt. % MgO increased the sintered density at the same oxygen pressure to 99.8%. Further MgO additions decreased the density. The density of pure MgO was independent of the P[subscript O₂] over the range investigated. Addition of Cr₂O₃ to MgO decreased the density at all oxygen pressures investigated. The largest decreases corresponded to the pressure ranges where the most volatile species in the Cr-O system appear. The weight loss was also monitored as a function of oxygen activity for all specimens. It was found to correlate with the changing predominant volatile species in the chrome-oxygen system. An anomalous weight loss of MgO was found at P[subscript O₂] <̲ 10⁻¹² atm which may be due to a volatile Mg-Cr oxide species"--Abstract, leaf ii. |
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"The effect of oxygen activity on the sintering of Cr₂O₃ with minor additions of MgO, and of MgO with minor additions of Cr₂O₃ at 1600°C was investigated. A peak density (99.4% of theoretical) was obtained for high purity Cr₂O₃ by maintaining the equilibrium oxygen partial pressure needed to maintain the Cr₂O₃ phase. The addition of 0.1 wt. % MgO increased the sintered density at the same oxygen pressure to 99.8%. Further MgO additions decreased the density. The density of pure MgO was independent of the P[subscript O₂] over the range investigated. Addition of Cr₂O₃ to MgO decreased the density at all oxygen pressures investigated. The largest decreases corresponded to the pressure ranges where the most volatile species in the Cr-O system appear. The weight loss was also monitored as a function of oxygen activity for all specimens. It was found to correlate with the changing predominant volatile species in the chrome-oxygen system. An anomalous weight loss of MgO was found at P[subscript O₂] ̲< 10⁻¹² atm which may be due to a volatile Mg-Cr oxide species"--Abstract, leaf ii. |
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