Cu纳米晶块体的制备及纳米晶粒长大动力学研究

Preparation and nanograin growth studies of Cu nanocrystalline bulk

采用高能球磨的方法制取金属纳米晶粉末，然后利用放电等离子烧结（SPS）技术制备出金属纳米晶块体材料。设计系列实验研究金属纳米晶材料的晶粒长大行为，获得了纳米晶粒长大的动力学规律。根据已有的工作基础和对实验结果的深入分析，确定动力学参数对稳定相晶粒长大行为的影响。实验发现了高能球磨配合SPS技术制备的Cu纳米晶块体发生快速晶粒长大的临界温度，并结合纳米晶界过剩体积与过剩自由能的关系，分析了纳米晶粒组织的能量因素对晶粒长大行为及动力学的影响。

Cu nanocrystalline bulk, prepared by the high-energy ball-milling and SPS technology, was used as an example to study the kinetic characteristics of nanograin growth at different temperatures. Based on the previous work in our group, we aimed to find out the relationship between the kinetics parameters and the stability of the nanocrystalline materials. In this work, the critical temperature for incontinuous nanograin growth in Cu nanocrystalline bulk has been found. Applying our previous analytical model that describes the thermodynamic functions of nanograin boundaries, the influences of the energy states of the nanostructure on the nanograin growth has been analyzed, and compared with the experimental results.