University of Miskolc, Egyetemvaros, Miskolc 3525, Hungary.
ELKH-ME Materials Science Research Group, Egyetemvaros, Miskolc 3525, Hungary.
Langmuir. 2023 May 9;39(18):6316-6323. doi: 10.1021/acs.langmuir.2c03336. Epub 2023 Apr 27.
Nanocomposites show the best performance when their reinforcing phase precipitates in situ from a matrix upon heat treatment and when coherency between the matrix and the reinforcing phase is preserved even upon coarsening the precipitated particles. In this paper, first a new equation is derived for the interfacial energy of strained coherent interfaces. From here, a new design rule is derived in a form of a new dimensionless number to select phase combinations for in situ coherent nanocomposites (ISCNCs). This is calculated from the molar volume mismatch between the two phases, their elastic constants, and the modeled interfacial energy between them. When this dimensionless number is smaller than a critical value, ISCNCs are formed. The critical value of this dimensionless number is found here using experimental data for the Ni-Al/NiAl superalloy. The validity of the new design rule was confirmed on the Al-Li/AlLi system. An algorithm is suggested to apply the new design rule. Our new design rule can be simplified to more easily available initial parameters: if the matrix and the precipitate have the same cubic crystal structure the precipitate is expected to form ISCNCs with that matrix if their standard molar volumes differ less than by about 2%.
当纳米复合材料的增强相在热处理时从基体中就地析出，并且即使在析出颗粒粗化时基体和增强相之间保持共格时，其性能表现最佳。在本文中，首先推导出了应变共格界面的界面能的新方程。由此，以新的无量纲数的形式推导出了用于原位共格纳米复合材料（ISCNC）的新设计规则，以选择相组合。该无量纲数是根据两相之间的摩尔体积失配、弹性常数以及它们之间的模拟界面能计算得出的。当这个无量纲数小于一个临界值时，就会形成 ISCNC。使用 Ni-Al/NiAl 高温合金的实验数据找到了这个无量纲数的临界值。在 Al-Li/AlLi 系统上验证了新设计规则的有效性。提出了一种应用新设计规则的算法。我们的新设计规则可以简化为更易于获得的初始参数：如果基体和析出物具有相同的立方晶体结构，如果它们的标准摩尔体积相差小于约 2%，则预计析出物将与该基体形成 ISCNC。
