直接晶化法制备块状纳米材料的探索──Ⅰ脉冲电流作用下无序金属介质的成核理论

EXPLORATION ON THE FABRICATION OF BULK NANOCRYSTALLINE MATERIALS BY DIRECT-NANOCRYSTALLIZING METHOD Ⅰ. Nucleation in Disordered Metallic Media by Electropulsing

利用经典热力学和连续介质电动力学理论计算了脉冲电流作用下无序介质（包括金属熔体和非晶态金属）的成核率．结果表明：对于无序介质的晶化过程，随脉冲电流密度增加，形核率成指数增大；超短时脉冲有可能使熔体直接冷凝成大块纳米晶材料，并能限制已经形成的纳米晶粒的长大．

Nucleation rate in disordered media (include melted metal and metglas) is calculated by using classical thermodynamics and electrodynamics. The results show that the nucleation rate has an exponential relationship to the pulsing electric current density. In the process of crystallization. the nucleation rate increases exponentially, ultra-short-time electropulsing may lead to the formation of bulk nanocrystalline materials, and the growth of some formed nanocrystallines are limited.