THE INFLUENCE OF PULSE ELECTRIC DISCHARGING ON SOLIDIFIED STRUCTURE OF Sn-10% Pb ALLOY
脉冲电流对Sn—Pb合金凝固组织的影响

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.