The influence of composite pulse current and static magnetic fields on the solidification structure formation in Pb–Zn alloys.

Pb–Zn alloy is an ideal anode material for zinc electrodeposition. In this work, the microstructure of Pb–Zn alloy is controlled by composite electro-magnetic fields (CEMFs), and the mechanism is investigated. The results show that electric current pulses (ECPs) can significantly enhance the nucleation driving force for the second phase, thereby promoting the refinement of the second phase. Static magnetic field (SMF) can substantially suppress melt convection and increase the melt cooling rate around the center axis of the sample. Therefore, it is favorable for the formation of a homogeneous dispersed microstructure along the radial direction. CEMFs not only can inhibit melt convection, but also enhance the nucleation rates of Minority Phase Droplets (MPDs). This promotes the formation of a solidification microstructure in which the fine Minority Phase Particles (MPPs) are homogeneously distributed in the matrix. This work indicates that the application of CEMFs is an effective method for controlling the microstructure of monotectic alloys and it has an important industrial value. [ABSTRACT FROM AUTHOR]