自蔓延高温合成MgCNi_3的热力学计算与分析  

Thermodynamics Calculation and Analysis of Self-Propagating High-Temperature Synthesis MgCNi_3

作　　者：何祖明[1] 夏咏梅[2] 郑明芳[1] 李书明[1] 

机构地区：[1]常州大学怀德学院,江苏常州213016 [2]兰州理工大学,甘肃兰州730050

出　　处：《常州大学学报（自然科学版）》2010年第4期11-14,共4页Journal of Changzhou University：Natural Science Edition

基　　金：卫星海洋环境动力学国家重点实验室开放课题(SOED0912)

摘　　要：对Mg-C-Ni3元体系进行了热力学计算,绘出了反应的标准自由焓随温度变化的曲线、绝热温度随Ni含量变化的曲线以及绝热温度随预热温度变化的曲线。分析表明:Mg-C-Ni体系的主要反应是Mg+C+3Ni=MgCNi3;体系的绝热温度随Ni含量的增加而下降,当预热温度为900K且绝热的条件下,理论计算Ni最佳的含量77.8%;若Ni含量过大,体系的绝热温度小于1800K时,可以适当的提高预热温度,来确保反应的自发进行;预热温度太低时不能点燃反应,预热温度应该大于893K,并且绝热温度随预热温度的升高而升高。According to the thermodynamic principles,the Mg-C-Ni system was thermodynamics calculated.The paper showed curves of standard free enthalpy with temperature changes,the curves of adiabatic temperature with Ni content changes and the curves of adiabatic temperature with preheating temperature.The analytic result showed that the main reaction formula of the three system was Mg＋C＋3Ni=MgCNi3.The adiabatic temperature of the system would descend as Ni content of the system increased.If preheating temperature was 900 K,the optimal theoretical Ni content was 77.8%.When the Ni content was too high and the adiabatic temperature of the system was under 1 800 K,heightening preheating temperature could insure that the reaction was spontaneous.The sample could not be ignited by electrical arc if the preheating temperature was too low.In the condition,MgCNi3 could be synthesized by SHS at over 893 K of preheating temperature.If the preheating temperature went up,the adiabatic temperature of the system would go up.

关 键 词：自蔓延高温合成 热力学 自由焓 绝热温度 

分 类 号：TG111.3[金属学及工艺—物理冶金]