Abstract
Joining of thermoplastic composite parts by induction heating using a susceptor sheet offers great perspective for lightweight applications. A new concept of metal-coated short fibers and metal-coated particles filled Polypropylene (PP) susceptor sheets was developed via melt mixing using double screw extruder and production by Calandering. In this work we investigated the heating behavior of metal-coated fibers and particles. During induction heating experiments, fiber heating by joule loss, dielectric heating, contact resistance heating as well as magnetic hysteresis effect were observed in fiber filled PP, however with particles filled PP only hysteresis effect was observed. Induction heating tests were performed on nickel coated carbon fibers and nickel coated graphite particles using a circular pane cake coil and at frequencies below 1 MHz. Time to reach temperature from 50 degrees C to 120 degrees C was calculated during induction heating experiments. Similar heating trend of fibers and particles filled PP were observed at lower concentrations, however, particles give better heating i.e. takes less to reach at high temperature. At higher concentrations it takes less time to reach at mentioned temperatures was observed in fibers due to above mentioned combined heating effects, while particles follow their trend of hysteresis effect. Electrical conductivity was measured by using four point measuring method and microstructure characterization were performed by Scanning electron microscopy (SEM) & X-ray computed microtomography (micro CT).