Lejček Pavel, Hofmann Siegfried, Paidar Václav
Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 1999/2, 182 21 Prague 8, Czech Republic.
Max-Planck-Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany.
Materials (Basel). 2019 Feb 5;12(3):492. doi: 10.3390/ma12030492.
The role of entropy in materials science is demonstrated in this report in order to establish its importance for the example of solute segregation at the grain boundaries of bcc iron. We show that substantial differences in grain boundary chemistry arise if their composition is calculated with or without consideration of the entropic term. Another example which clearly documents the necessity of implementing the entropic term in materials science is the enthalpy-entropy compensation effect. Entropy also plays a decisive role in the anisotropy of grain boundary segregation and in interface characterization. The consequences of the ambiguous determination of grain boundary segregation on the prediction of materials behavior are also briefly discussed. All the mentioned examples prove the importance of entropy in the quantification of grain boundary segregation and consequently of other materials properties.
本报告展示了熵在材料科学中的作用，以确立其对于体心立方铁晶界溶质偏析示例的重要性。我们表明，如果在计算晶界成分时考虑或不考虑熵项，会产生显著的晶界化学差异。另一个清楚证明在材料科学中纳入熵项必要性的例子是焓 - 熵补偿效应。熵在晶界偏析的各向异性和界面表征中也起着决定性作用。还简要讨论了晶界偏析测定不明确对材料行为预测的影响。所有上述例子都证明了熵在量化晶界偏析以及其他材料性能方面的重要性。
