THEORY OF SOLID SOLUBILITY FOR RARE-EARTH-METAL BASED ALLOYS

Both parabola and ellipse separating schemes are used to study the sol id solubilities for the binary alloy systems based on the 13 rare eart h metals. It has been found that the soluble elements can be separated from the insoluble ones by a parabola y(1) = a - bx(1)(2) or an ellip se (x(2)-m)(2)/c(2) + (y(2)-n)(2)/d(2) = 1. The results show that the overall reliabilities of the solid solubilities for the 897 binary all oys based on the rare earth metals are 89.2% and 92.8% for the parabol a and ellipse regularities respectively. The constants a and b in the parabola equation, and m, n, c and d in the ellipse equation are discu ssed, which can be related to some appropriate parameters for each hos t metal respectively.