Uniform dispersion of steel fibers in silicone composites via an externally applied magnetic field

Abstract

• Steel fibers in composites settle and agglomerate during curing. • Fiber dispersion improved by 20% for composites cured under a magnetic field. • Magnetized composite samples also exhibited a uniform electrical resistance. Steel fiber-reinforced silicone composites do not suffer from fiber breakage during mixing due to the highly ductile nature of steel fibers. However, conventional methods for dispersing steel fibers in the silicone matrix lead to fiber settlement and agglomeration. In this paper, we propose using an applied magnetic field to achieve a uniform dispersion of steel fibers in silicone. We examined composite samples containing 4 mm-long steel fibers at weight fractions of 0.7%, 0.9%, and 1.1%. The magnetic field was applied during the curing stage by placing two neodymium magnets at both ends of the composite mixture. Optical and scanning electron microscopy images and electrical resistance measurements were analyzed to evaluate the efficacy of the proposed method. Fiber dispersion was improved in magnetized composite samples as evidenced by reduced settlement and agglomeration.