Additive Manufacturing of Magnetically Loaded Polymer Composites: An Experimental Study for Process Development

Material jetting is an additive manufacturing technique that allows to produce three-dimensional solid parts without tooling and with minimum material wastage. In this context, magnetically loaded polymer composites with oriented magnetic particles are promising for many electrical and electronic applications. In this study, permanent magnet based alignment configurations were evaluated and compared in terms of different magnetic flux density using the finite element method. The particle alignment in cured droplet specimens and the stability of magnetically loaded polymer droplets deposited on a substrate were characterized for a material jetting based additive manufacturing process. Particle alignment and droplet deformation under the influence of the magnetic field was captured using real-time optical microscopy. The influence of rheological additives in controlling droplet stability in the magnetic field and mitigating particle settling were studied through experiments. The primary goal of this research was to identify parameters that facilitate high particle alignment, and material combinations that enhance droplet stability and mitigate particle settling. This fundamental research serves to enhance the understanding of processes and material behaviour for material jetting based additive manufacturing.