Extracted By The Binary Phase Diagram Activity Studies

Based on methods of calculating activities from binary phase diagrams, The component activity data of 42 binary liquid alloys are calculated under the conditions of regular solution's and Richardson's assumption. The total average relative errors of two components between calculated values and experimental data under regular solution's assumption are as follows:For simple eutectic phase diagrams, the results are 6.69% and 6.45%; For phase diagrams containing solid solution, the results are 7.18% and 6.68%; For phase diagrams involving intermediate compounds, the results are 19.7% and 17.8%; For phase diagrams involving two liquid phase, the results are 7.36% and 6.64%. The total average relative errors of two components between calculated values and experimental data under Richardson's assumption are as follows:For simple eutectic phase diagrams, the results are 7.36% and 7.07%; For phase diagrams containing solid solution, the results are 5.99% and 5.74%; For phase diagrams involving intermediate compounds, the results are 17.3% and 16.3%; For phase diagrams involving two liquid phase, the results are 5.25% and 5.55%; The study results show that methods of calculating activities from simple eutectic phase diagrams and phase diagrams containing solid solution or involving two liquid phase are quite efficient, the effectiveness of method is relatively poor for phase diagrams involving intermediate compounds. Besides, The accuracy of the calculated values is small improved after introduced Richardson's assumption.The infinite dilute activity coefficient of two components of 40 binary liquid alloys are calculated after introduced the function ofα. The total average relative errors of two components between calculated values and experimental data under regular solution's assumption are as follows:For simple eutectic phase diagrams, the results are 28.5% and 29.3%; For phase diagrams containing solid solution, the results are 26.5% and 23.2%; For phase diagrams involving intermediate compounds, the results are 32.2% and 67.6%; For phase diagrams involving two liquid phase, the results are 50.6% and 42.6%. The total average relative errors of two components between calculated values and experimental data under Richardson's assumption are as follows:For simple eutectic phase diagrams, the results are 22.0% and 22.3%; For phase diagrams containing solid solution, the results are 26.6% and 21.1%; For phase diagrams involving intermediate compounds, the results are 38.6% and 70.1%; For phase diagrams involving two liquid phase, the results are 12.4% and 19.4%; The study results show that methods of calculating infinite dilute activity coefficient of two components from simple eutectic phase diagrams and phase diagrams containing solid solution are relatively efficient, the total average relative errors of two components are in less than 30%. The effectiveness of method is relatively poor for phase diagrams involving two liquid under regular solution's assumption, but the calculated values are approaching experimental data under Richardson's assumption, the total average relative errors of two components are in less than 20%. The effectiveness of method is relatively worse for phase diagrams involving intermediate compounds. The activity and infinite dilute activity coefficient of two components of 5 Rare earth binary alloy system are predicted, there are Cr-Lu (2173K),Mo-Nd (3700K),Mo-Pr (3700K),Lu-Mo (2900K),Ho-Mo (3100K).The component activity data of 5 binary molten slag are calculated from phase diagrams. The total average relative errors of two components between calculated values and experimental data are 6.77% and 5.96% under regular solution's assumption, and are 9.55% and 8.44% under Richardson's assumption. The study results show that methods of calculating activities from binary molten slag phase diagrams are feasible, especially when lack of experimental data.Based on the relationship between infinite dilute activity coefficient of component and temperature, The modified formulas of calculating activity from binary phase diagrams were deduced. The component activity data of 42 binary liquid alloys are calculated by using these modified formulas. The total average relative errors of two components between calculated values and experimental data are as follows:For simple eutectic phase diagrams, the results are 6.61% and 6.23%; For phase diagrams containing solid solution, the results are 4.89% and 4.44%; For phase diagrams involving intermediate compounds, the results are 26.6% and 27.1%; For phase diagrams involving two liquid phase, the results are 3.93% and 4.44%; By the comparer of calculated result between modified formulas and Zhou guozhi's formulas, For simple eutectic phase diagrams,phase diagrams containing solid solution and phase diagrams involving two liquid phase, modified formulas is a little superior than Zhou guozhi's formulas. But for phase diagrams involving intermediate compounds, the results are opposite.