Effect of permanent magnet stirring on solidification of Sn-Pb alloy

An experimental investigation has been conducted with respect to the influence of permanent magnet stirring (PMS) under different rotation speeds (omega = 60, 120 and 150 r/min) and center magnetic flux densities (B = 757 and 1080 Gs) on the solidification of Sn-20 wt%Pb alloy. The magnetic field was generated by a pair of arc shaped NdFeB permanent magnets with a gap that could be adjusted to obtain the required magnetic flux density. The effects of different values of omega and B were investigated by analyzing the driven flow intensity, surface and internal quality, macrostructure, microstructure and tensile properties. It was observed that with increasing omega and B there was significant improvement in the flow intensity of the liquid, surface pinholes, grain refinement and tensile properties. The results obtained have important implications for industrial metal casting processes. (C) 2016 Elsevier Ltd. All rights reserved.