(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 目前在二元相图中普遍存在两个被疏忽的问题：一是关于二元系中许多中间相在某一温度发生晶型转变时如何表示的问题，在已发表的二元相图资料中，大部分用水平实线或虚线来表示这种晶型转变，而二元相图中水平实线或虚线通常是用来表示三相平衡的等温反应，但中间相的晶型转变不是三相平衡的等温反应，所以，不能用实线或虚线来表示；二是对某些沸点较低的组元，在温度高于其沸点温度时，靠近这些组元的端际单相区应该是气相，而许多二元相图中仍然标为液相。本文作者认为应该重视由于疏忽而产生的这两类问题，并加以改正，以免让读者产生误解。
关键字: 二元相图；中间相晶型转变；液−气相态转变
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Two usually over looked problems are in the binary phase diagrams. First, the crystal style of many interphases would transit in the binary systems, the crystal style transition was shown by horizontal full line or dashed line in most of the published binary phase diagrams. Horizontal full line in binary phase diagram presents the isothermal reaction of three-phase equilibrium. But crystal shape transition of the interphase is not an isothermal reaction of three-phase equilibrium, therefore it can not be presented by horizontal full line or dashed line. Second, to some components with low boiling point, when the temperature is higher than their boiling points, the head monophase field next to the components should be gas phase, which was still marked as liquid phase in many binary phase diagrams. This is also an missing error. The author suggests that the two neglected problems should be paid great attention and corrected to avoid misunderstanding.
Key words: binary phase diagram; interphase crystal shape transition; liquid-gas phase state change
