机械合金化制备Ag-Cu纳米晶过饱和固溶体

Mechanical alloying of Ag-Cu nanocrystalline supersaturated solid solution

参考Miedema半经验理论,建立了Ag-Cu系机械合金化(MA)过程的热力学模型。热力学计算分析指出,Ag-Cu二元系不具有形成过饱和固溶体的热力学驱动力;而对机械合金化制备的Ag-20%Cu(原子分数)合金的X射线衍射(XRD)分析表明,机械合金化可以获得Ag-Cu纳米晶过饱和固溶体;这说明Ag-Cu合金经机械合金化形成过饱和固溶体主要来源于动力学驱动。在随后的退火过程中,纳米晶过饱和固溶体发生分解。

The thermodynamics model of Ag-Cu system in mechanical alloying （MA） process was established based on Miedema semi-experimental theory. The calculation result shows that there is no thermodynamics driving force to form solid solution. While the X-ray diffraction （XRD） result shows that Ag-20%Cu （atom percent） nano- crystalline supersaturated solid solution can be prepared by mechanical alloying. The driving force of Ag-Cu super- saturated solid solution prepared by mechanical alloying comes from kinetics driving force. In the subsequent an- nealing process, the nanocrystalline supersaturated solid solution decomposes.