摘要
One of the key parameters in calculating the paths of solidifications is the distribution coefficient. This coefficient, usually referred to as k, is the compositional ratio of the coexisting solid and liquid at the interface at a given temperature. This value is usually assumed to be a constant for this type of calculation. 1.2 Sometimes values of k are taken directly from the binary phase diagram. 3,4 However, if appropriate thermodynamic models are available, values of k can be calculated as a function of temperature. The calculated values can then be used directly to compute the paths of solidification using a solidification model such as the Scheil model. This approach is highly desirable in view of the recent development in thermodynamic modeling and phase diagram calculation, on the one hand, and the availability of personal computers, on the other. While this approach is desirable for binary systems, it is essential for ternary and higher order systems. For a ternary system, even for a system of commercial importance, the phase diagram is known usually at one and perhaps two temperatures. © 1975, American Society for Metals, The Melallurgical Society of AIME. All rights reserved.