Abstract:The solidification process is a core part in the preparation of alloy, which determines its as-cast microstructure and properties. In this work, the effect of rotating magnetic field (RMF) with varying currents on the solidification microstructure and properties of Cu-Cr-Zr-Si alloy under vacuum was investigated. The microstructure results revealed that the grain size decreases with the increase of magnetic field current. When the magnetic field current increased from 40 to 120 A, the grain size of the matrix was refined from 270 to 58 μm. In addition, it was also observed that the grain morphology gradually changed from columnar to equiaxed, and the proportion of equiaxed crystal region increased with the increase of magnetic field current. The properties analysis showed that compared with the alloy without RMF, the ultimate tensile strength (UTS) was increased by 6.1%, 7.3% and 19.2%, the yield strength (YS) was increased by 6.1%, 10.2% and 19.4%, and the elongation (EL) was increased by 17.4%, 26.1% and 60.9%, respectively, under the condition that the magnetic field current I=40, 80 and 120 A. The increase of strength and ductility was mainly attributed to grain refinement and the increase of the proportion of equiaxed grains. The conductivity was largely unaffected by RMF with varying currents. Therefore, the application of rotating magnetic field during solidification was considered to be a key technology for controlling microstructure to achieve performance improvement and enabling large-scale production.