(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 目前在二元相圖中普遍存在兩個被疏忽的問題：一是關(guān)于二元系中許多中間相在某一溫度發(fā)生晶型轉(zhuǎn)變時如何表示的問題，在已發(fā)表的二元相圖資料中，大部分用水平實線或虛線來表示這種晶型轉(zhuǎn)變，而二元相圖中水平實線或虛線通常是用來表示三相平衡的等溫反應(yīng)，但中間相的晶型轉(zhuǎn)變不是三相平衡的等溫反應(yīng)，所以，不能用實線或虛線來表示；二是對某些沸點較低的組元，在溫度高于其沸點溫度時，靠近這些組元的端際單相區(qū)應(yīng)該是氣相，而許多二元相圖中仍然標為液相。本文作者認為應(yīng)該重視由于疏忽而產(chǎn)生的這兩類問題，并加以改正，以免讓讀者產(chǎn)生誤解。
關(guān)鍵字: 二元相圖；中間相晶型轉(zhuǎn)變；液−氣相態(tài)轉(zhuǎn)變
（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
