Mg-Zn粉末机械合金化非晶转变

The Amorphization Transformation of Mg and Zn Powders by Means of Mechanical Alloying

采用纯金属镁粉和锌粉为原料,通过机械合金化制取了Mg-Zn非晶合金粉末。借助扫描电镜(SEM)、透射电镜(TEM)、X-射线衍射仪、能谱分析仪等手段研究了Mg_(50)Zn_(50)粉末的机械合金化非晶转变过程。本实验证明了镁基合金在负值混合焓较小的条件下,可以通过机械驱动力的作用而发生MA非晶反应,且非晶反应能力很强,Mg_(50)Zn_(50)在50h内完成了非晶转变。非晶反应可能与颗粒的变形细化过程有关,原子的界面扩散在非晶反应过程中起重要作用。

It is for the first time that Mg-Zn ancorphous alloy powder has been systhesized successfully by mechanical alloying of pure magnesium and zinc powders, in a specific vibrating mill. Amorphization process of Mg50Zn50 alloy powder depending on MA was studied,by means of X-ray diffractometer,SEM,TEM and spectrometer. Generally it was thought that in mechanical alloying of binary metal system the amorphization ability are high enough only when Hmin<<0 and DB>> DA. As to Mg-Zn system the condition Hmin<0 is not met,So that the amorphization would be extremely difficult. In this experiment it is proved that in the Mg-Zn system the amorphization depending on MA of both pure elements can be realized even when the negative value of mixing enthalpy is very slow. The reaction was both chemirally and mechanically driven and finished within 50 hours. There is a possibility that the process of amorphiration of the powders was connected with the process of becoming finer.