YbCl_3－CaCl_2－MgCl_2三元体系液相限的研究

AN INVESTIGATION ON THE LIQUIDUS OF TERNARY SYSTEM YbCl_3-CaCl_2-MgCl_2

借助于ＤＴＡ测定了ＹｂＣｌ３－ＣａＣｌ２－ＭｇＣｌ２三元体系液相限．发现本体系有对应于ＹｂＣｌ３、ＣａＣｌ２、ＭｇＣｌ２和不稳定化合物Ｘ的四个液相面，五条二次结晶线，一个三元低共熔点Ｅ（３８．０ｗｔ％ＹｂＣｌ３，３１．０ｗｔ％ＣａＣｌ２，３１．０ｗｔ％ＭｇＣｌ２；５５６℃）和三元转熔点Ｐ’（４５．５ｗｔ％ＹｂＣｌ３，２８．０ｗｔ％ＣａＣｌ２，２６．５ｗｔ％ＭｇＣｌ２；６００℃）．

The liquidus of ternary system YbCl3-CaCl2-MgCl2 has been investigated by means of DTA. It was found that there arc four surfaces coryesponding to the primary crystallization of YbCl3, CaCl2, MgCl2 and unstable compound X respectively, and five univariant curves to the secondary ctystallization. The temperature of the ternary cutectic, composed of 38.0wt%YbCl3, 31 .0wt% CaCl2, 31 .0wt% MgCl2, was determined to be 556℃. The temperature of the ternary peritecti-like, composed of 45.5wt% YbCl3, 28.0wt% CaCl2, 26.5wt% MgCl2, was observed to be 600℃.