Formation of polycrystalline-Co particle-chains in Cu–Co alloy during liquid-phase sintering in a high magnetic field

Liquid-phase sintering of Cu–30 wt.% Co alloy, involving liquid Cu coexisting with solid Co particles, was performed with and without a 12 T magnetic field. The microstructure evolution and coarsening behavior of polycrystalline Co particles during the sintering were investigated. The Co particle size increased with increasing sintering time, both with and without the high magnetic field; however, the application of the high magnetic field led to larger Co particles through a higher coarsening velocity. Additionally, under the high magnetic field, chain-like Co particle structures were formed. The coarsening and chain-like structure of the polycrystalline Co particles in the high magnetic field could be linked to the alignment of the magnetic domains in the particles and the induction of magnetic dipole–dipole interactions between particles, which promoted contact between Co particles. This study provides guidance and reference for the use of high magnetic fields to control liquid-phase sintering of polycrystalline particles.