Investigations on the trajectories of magnetic abrasive grains in magnetic induction-free abrasive wire sawing

This study presents a novel method of magnetic induction-free abrasive wire sawing. The ferromagnetic wire is magnetized in a uniform magnetic field, forming a high-gradient magnetic field that separates into paramagnetic and diamagnetic regions. Paramagnetic abrasive grains are attracted to the paramagnetic region and adhere to the wire surface but are repelled from the diamagnetic region. The trajectory of the magnetic abrasive grains is analyzed in a mathematical model and in COMSOL Multiphysics simulations. The results are verified by test investigations on the motions and adsorption of the magnetic abrasive grains using a dynamic microscope system. The detailed grain trajectories are investigated in a numerical model. Because it actively transports grains toward the wire (where they can be transported to the sawing channel), our proposed method achieves more efficient wire sawing performance than traditional free abrasive wire sawing. Such efficient performance is highly sought in silicon wafering technologies, which are commonly used in the solar and semiconductor industries.