Interpolation and extrapolation with the CALPHAD method

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2019,（9）
• 页码范围: 2115-2120
• 页数: 6页
• 语种: 英文

摘要

It is widely reported that CALPHAD is an extrapolation method when the thermodynamic properties of a multicomponent system are approximated by its subsystems.In this work the meaning of the words extrapolation and interpolation is discussed in context of the CALPHAD method.When assessing the properties in binary and ternary systems,extrapolation method is indeed often used.However,after assessment,the Gibbs energies are in fact interpolated from the lower order systems into the higher order systems in the compositional space.The metastable melting temperatures of bcc and hcp in Re-W and the liquid miscibility gap in Mg-Zr system are predicted to illustrate the difference between interpolation and extrapolation.