MoSi_2-WSi_2复合材料自蔓延热爆合成反应热力学  

Reaction Thermodynamics of MoSi_2-WSi_2 Composites in the Thermal Explosion Mode of SHS

作　　者：彭可[1] 易茂中[1] 冉丽萍[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《稀有金属材料与工程》2006年第4期554-558,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助项目(50472078)

摘　　要：对Mo-W-Si三元体系自蔓延热爆合成MoSi2-WSi2复合材料的反应吉布斯自由能、反应生成焓和绝热温度进行了理论分析和实验研究,并利用X射线衍射分析和扫描电镜及微区成分分析(EDAX)技术对产物进行了相组成和微区成分分析。结果表明:在1685K(Si熔点)时,MoSi2和WSi2的反应生成焓最大,分别为234.645kJ/mol和195.670kJ/mol。当初始温度为1685K时,体系所有产物均完全熔融。利用自蔓延热爆合成可制备纯净的MoSi2-WSi2复合材料。MoSi2和WSi2以固溶体(Mox,W1-x)Si2的形式存在,但每个晶粒内的成分并不均匀。The reactive Gibbs free energies, the reactive formation enthalpies and adiabatic temperatures concerning the preparation of MoSi2-WSi2 composites using elemental powders of Mo, W and Si by the thermal explosion mode of SHS have been theoretically calculated and investigated by experiments. XRD, SEM and EDAX have analyzed the phase compositions and micro-area chemical analyses of the products. The results show that the reactive formation enthalpies of MoSi2 and WSi2 are biggest, 234.645 kJ/mol and 195.670 kJ/mol respectively, when the reactions take place at 1685 K (the melting point of Si). And when the initial temperature is 1685 K, the products of all systems have fused completely. Pure MoSi2-WSi2 composites are fabricated by the thermal explosion mode of SHS, and MoSi2-WSi2 exists as solid solution of (Mo-x,W1-x)Si-2 while the chemical elements of every grain are not uniform.

关 键 词：MoSi2-WSi2复合材料 自蔓延热爆合成 反应热力学 绝热温度 

分 类 号：TB331[一般工业技术—材料科学与工程]