氧对Mo-Si系机械合金化的影响

INFLUENCE OF OXYGEN ON MECHANICAL ALLOYING OF A Mo-Si SYSTEM

本文通过比较在清洁和含氧环境中 Ｍｏ－Ｓｉ混合粉末（Ｍｏ３３Ｓｉ６７）的机械合金化过程，研究了氧对 Ｍｏ／Ｓｉ 固态反应的影响．采用 Ｘ射线衍射和透射电镜检测了 Ｍｏ—Ｓｉ混合粉末在两种球磨条件下的结构变化，结果发现：在清洁环境中，高能球磨能诱导Ｍｏ／Ｓｉ之间的完全反应，并导致室温相α－ＭｏＳｉ２和高温相β－ＭｏＳｉ２的形成．然而在含氧环境中，氧的侵入不但大大减缓Ｍｏ／Ｓｉ固态反应及金属硅化物的形成速度，而且还导致已形成的稳定硅化物的分解，文中从热力学和动力学两方面分析了氧对

In this paper, the influence of oxygen contamination on mechanical alloying of Mo-Si powder mixture (MO33Si67) has been investigated by X-ray diffraction and transmission electron microscopy. It is found that a complete Mo/Si reaction with the formation of both low temperature phase alpha -MoSi2 and high temperature phase beta -MoSi2 can take place if oxygen is kept under control. However, if the milling is proceeding in an atmosphere containing oxygen, oxygen pick-up can strongly inhibit the Mo/Si solid state reaction, and even cause the destabilization of the already formed intermetallic compounds. The influence of oxygen contamination has been discussed from both thermodynamic and kinetic aspects.