碳化钒有序-无序相变的热力学研究  

Thermodynamic Study of Order-disorder Phase Transition of Vanadium Carbide

作　　者：罗奕兵[1] 颜练武[2] 

机构地区：[1]长沙理工大学汽车与机械工程学院工程车辆轻量化与可靠性技术湖南省高校重点实验室,湖南长沙410004 [2]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2015年第2期79-82,共4页Cemented Carbides

基　　金：湖南省教育厅科技计划资助项目(14C0043);工程车辆轻量化与可靠性技术湖南省高校重点实验室开放基金

摘　　要：本文分析了碳化钒由无序相转变为有序相转变的热力学问题,建立了基于碳化钒中不同类型键相互作用与熵值和自由能的函数关系,求解了碳化钒由无序相转变为有序相转变后碳原子和空位的有序度,结合粉末的DSC的测定曲线和XRD衍射分析表明:在T=1 515 K时,碳化钒粉末存在有序-无序相变,其具有一阶相变特征,有序度将由0.23突变为0。Thermodynamic process of phase transition from disorder to order of vanadium carbide was studied in this paper. Based on interaction energy and number of different bonds, the function relationship between entropy and free energy in vanadium carbide was established. The order degree of carbon atom and vacancy in vanadium carbide crystals was obtained. Combined with DSC and XRD results, it is concluded that there is order-disorder transition at temperature of 1 515 K. The transition externalizes distinction of first-order phase transition. The degree of order decreases from 0.23 to 0 suddenly.

关 键 词：碳化钒 相变 有序-无序 

分 类 号：TQ135.11[化学工程—无机化工]