Characterization of magnetic particle alignment in photosensitive polymer resin: A preliminary study for additive manufacturing processes

Material jetting 3D printing is an additive manufacturing technique that allows producing complex parts without tooling and minimum material wastage. In this study, orientation control of randomly shaped, anisotropic hard magnetic ferrite particles is demonstrated for material jetting-based additive manufacturing processes using a developed particle alignment configuration. Strontium ferrite and PR-48 photosensitive resin were used as the base materials. An automated experimental setup with two neodymium permanent cube magnets capable of generating a dipolar magnetic field was built to align magnetic particles in the resin. Particle alignment was characterized for directionality using images obtained through real time optical microscopy. The orientation of magnetic particles was observed to be dependent on the distance of separation between the cube magnets and the magnetization time. X-ray diffraction was used to indicate the c-axis alignment of the hexagonal strontium ferrite particles in the cured specimens. The influence of process parameters on particle orientation was evaluated, employing a full factorial experiment analysis. This fundamental research serves as a basis for constructing and optimizing the magnetic particle alignment setup for additive manufacturing processes.