Phase Diagrams: The Beginning of Wisdom
Phase Diagrams: The Beginning of Wisdom
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DOI：
10.1007/s11669-014-0343-5
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发表时间：
2014-09
影响因子：
1.4
通讯作者：
R. Schmid-Fetzer
中科院分区：
文献类型：
--
作者：
R. Schmid-Fetzer
这项工作介绍了在当前强大的热力学软件包环境中“如何阅读和应用相图”的入门知识。还涵盖了该上下文中的高级方面。它是材料科学和工程知识基石的简要指南，并为正确解释最先进的 Calphad 型热力学计算结果提供帮助。它从基础知识开始，解释了一元、二元和三元相图的读取，包括液相线投影、等温和垂直相图部分。应用示例直接源自 Fe、Cu-Ni、Mg-Al 和 Mg-Al-Zn 的这些相图。解释了相关 Fe-C 和 Fe-C-Si 系统中稳定和亚稳态相图的使用以及状态变量的适当选择。通过回到 Cu-Ni 和 Mg-Al-Zn 系统，可以清楚地了解多组分系统相图部分中零相分数线的最有用概念。使用 Scheil 近似与平衡情况进行比较的热力学凝固模拟在多组分多相凝固的背景下进行了介绍，并以 Mg-Al-Zn 合金为例。通用方法直接适用于所有无机材料，但在本简明工作中举例说明了一小部分金属系统，以强调相图之间的相互依赖性。真实材料系统和各种材料过程的嵌入式应用示例还强调使用相图来表示从初始非平衡状态到平衡的路径。
This work presents a primer on “How to Read and Apply Phase Diagrams” in the current environment of powerful thermodynamic software packages. Advanced aspects in that context are also covered. It is a brief guide into using this cornerstone of knowledge in materials science and engineering and offers assistance in the proper interpretation of results obtained from state-of-the-art Calphad-type thermodynamic calculations. Starting from the very basics it explains the reading of unary, binary and ternary phase diagrams, including liquidus projections, isothermal and vertical phase diagram sections. Application examples are directly derived from these phase diagrams of Fe, Cu-Ni, Mg-Al, and Mg-Al-Zn. The use of stable and metastable phase diagrams and appropriate choices of state variables are explained for the relevant Fe-C and Fe-C-Si systems. The most useful concept of zero-phase fraction lines in phase diagram sections of multicomponent systems is made clear by coming back to the Cu-Ni and Mg-Al-Zn systems. Thermodynamic solidification simulation using the Scheil approximation in comparison to the equilibrium case is covered in context of multicomponent multiphase solidification and exemplified for Mg-Al-Zn alloys. The generic approach is directly applicable for all inorganic materials, but exemplified in this concise work for a small selection of metallic systems to highlight the interdependences among the phase diagrams. The embedded application examples for real material systems and various materials processes also emphasize the use of phase diagrams for the path from initial off-equilibrium state towards equilibrium.