Premium
Effects of flow induced orientation of ferromagnetic particles on relative magnetic permeability of injection molded composites
Author(s) -
Fiske Thomas,
Gokturk Halit S.,
Yazici Rahmi,
Kalyon Dilhan M.
Publication year - 1997
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11725
Subject(s) - materials science , composite material , composite number , volume fraction , permeability (electromagnetism) , polyolefin , mold , ferromagnetism , molding (decorative) , fiber , relative permeability , magnetic field , porosity , genetics , physics , layer (electronics) , quantum mechanics , membrane , biology
Composite samples consisting of ferromagnetic asymmetric particles incorporated into a polyolefin binder were injection molded using custom designed molds which produced preferential fiber orientations. The relative magnetic permeability values of the composites were measured as a function of the filler volume fraction, injection rate, gate diameter, temperature, aspect ratio of the fibers, and fiber orientation. Fiber orientation was affected by the molding conditions and controlled the relative magnetic permeability of the composites. The degree of fiber orientation was significantly affected by the size of the opening (gate) to the mold, or by the mold geometry going from an edge‐gated cylindrical to a center‐gated disk cavity. Relative permeability values of the composites were observed to increase when the fiber orientation and the applied field were parallel to one another. For instance, highly aligned composite samples exhibited up to 30% greater relative permeability values compared to those samples which exhibit fiber orientation distributions approaching a random distribution. To our knowledge this is the first study that provides data linking the fiber orientation distribution functions of ferromagnetic asymmetric particles to the relative magnetic permeability values of injection molded composites.