摘要
研究了脉冲电流对Sn－10％Pb合金凝固组织的影响。实验表明：粗大的富Sn树枝状初晶细化成近球状结构，提出了一个脉冲电流对凝固组织影响的唯象机制，用经典的均匀形核理论和电动力学理论导出了脉冲压力与脉冲电流之间和成核率与脉冲压力之间的关系，脉冲电流产生的大小不同的脉冲压力对晶核的形成和长大产生不同程度的影响是导致不同观测结果的基本原因。
The influence of PED (pulse electric discharging) on the solidified structure of Sn-10%Pb (mass fraction) hypoeutectic has been studied. The testing results show that the PED can modify the solidified structure from large grains with Sn-rich dendrites to finer grains with nearly globular crystals. A phenomenological mechanism has been proposed to approach how the PED affects the microstructure. The relationships between the pulse pressure and pulse current, and between the nucleation rate and pulse pressure have been derived using the classical homogeneous nucleation theory and electrodynamic theory. The different results, tested here and elsewhere, may result from the different influence of PED on nucleation and growth of grains because of the different pulse pressure with various PED.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第4期352-358,共7页
Acta Metallurgica Sinica
基金
国家自然科学基金
关键词
凝固组织
脉冲电流
成核率
锡铅合金
Sn-Pb alloys, solidified microstructure, pulse electric discharging, pulse pressure, nucleation rate
