Plastomagnets are a type of composite consisting of magnetic powders, a polymeric binder, and various additives. Today, there are many types of these materials used in various fields, but they are particularly important in the automotive industry. The development of these composites aims to produce affordable materials for manufacturing products with complex shapes and high dimensional tolerances, and they are easier to process into final forms compared to sintered magnets. Due to these properties, despite having somewhat lower magnetic properties, they are increasingly competing with traditional sintered permanent magnets.
As part of a master's thesis, we investigated how the addition of a liquid crystalline polymer (LCP) affects the mechanical and magnetic properties of a plastomagnetic material based on NdFeB magnetic powder and a polyphenylene sulfide (PPS) binder. We also tested four different additives: two to improve compatibility between the polymers used and two to increase polymer fluidity. Through compounding and granulation processes, we produced a series of plastomagnetic materials, altering the composition of the polymer matrix by adding various proportions of liquid crystalline polymer and additives. However, we did not alter the proportion and composition of the NdFeB magnetic powder. Using injection molding technology, we manufactured samples on which we performed density and magnetic properties measurements, as well as tensile and three-point bending tests. The polymers used were analyzed using differential scanning calorimetry (DSC), and the plastomagnetic granulates were analyzed for melt flow index (MFI). Finally, we conducted metallographic analysis on the specimens to determine their mechanical properties. The measurement results were analyzed and compared, primarily focusing on the base material without the addition of LCP and additives.
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