Mo-Si系机械合金化非晶转变

AMORPHIZATOIN OF Mo AND Si POWDER BY MA

利用透射电镜和Ｘ射线衍射技术研究了Ｍｏ－３６．５％Ｓｉ、Ｍｏ－４５％Ｓｉ和Ｍｏ－６６．７％Ｓｉ混合粉在机械合金化过程中的相结构变化。经长时间球磨后，这三种粉都可以转变为非晶；不同成分混合粉的中间产物并不相同，中间产物的差异导致了不同成分的Ｍｏ－Ｓｉ系非晶转变的机制不同。Ｍｏ－３６．５％Ｓｉ的非晶化过程是首先形成亚稳相的过饱和固溶体，然后形成了非晶，此时，Ｍｏ和Ｓｉ原子的尺寸因素是非晶转变的决定因素。Ｍｏ－４５％Ｓｉ和Ｍｏ－６６．７％Ｓｉ混和粉则是首先形成了金属间化合物，然后形成了非晶相，此时，缺陷为非晶转变的决定因素。

The amorphization of elemental Mo and Si powder upon mechanical alloying(MA) was studied by X-ray diffraction and TEM. After long time grinding, Mo_36.5%Si, Mo_45%Si and Mo_66.7%Si mixture powders could be amorphized, but different powders had different middle products. The difference made the mechanism of amorphization different. First the amorphization procession of Mo_36.5%Si formed supersaturated solid solution, then formed amorphous state. That of Mo_45%Si and Mo_66.7% Si first formed intermetallic compound, then formed amorphous state.