摘要
利用行星式球磨机、X射线衍射仪和差热分析仪研究了Mo和Si元素混合粉末的机械合金化行为.结果表明,随着球磨时间的延长,Mo,Si混合粉末中首先形成Mo(Si)超过饱和固溶体,随后相继出现C40型h-MoSi2和Cllb型t—MoSi2纳米晶,最终的产物是以h—MoSi2纳米晶为主的非晶粉末混合物.
The microstructural evolution of mechanical alloyed Mo-67%Si powders using the planetary ball mill has been studied by X ray diffractometer (XRD) and differential thermal analyzer (DTA). The result shows that the hexagonal (h) MoSi2 and tetragonal (t) MoSi2 nanocrystallites formed in succession as the intermediate products of mechanical alloyed Mo/Si powders, and the final products are a mixture of h-MoSi2 microcrystallites and amorphous elemental Mo and Si powders.Additionally the reason why the h- MoSi2 phase predominates over t-MoSi2 phase in the mechanicalalloyed powders mixture has been explained on the basis of the concept of the nuclei of h-MoSi2 forming likely from the stacking faults on the {110} plane of t- MoSi2 phase during mechanical alloying process.For this reason, h-MoSi2 is a kind of low temperature metastable phase closer to amorphous state than t-MoSi2 in free energy.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
1998年第3期267-271,共5页
Chinese Journal of Materials Research
关键词
固态相变
机械合金化
钼
硅
混合粉末
solid reaction,h-MoSi_2,t-MoSi_2, mechanical alloying, stacking fault