Rheological Properties of Magnetorheological Elastomer Using Cobalt Powder as Filler

Abstract

Carbonyl iron particles (CIP) have been widely used as magnetic particles in magnetorheological elastomer (MRE) fabrication. This kind of magnetic particle exhibits high magnetic saturation however low conductivity. Therefore, in this study, cobalt particle has been introduced as filler in MRE fabrication. It is well known that cobalt offered dual properties which are magnetic and electrical properties. The properties offered by the cobalt are believed to enhance the magnetic and rheological properties of the isotropic MRE. Therefore, the isotropic MRE was fabricated using silicone rubber (SR) as the matrix element interspersed with 53 wt% of cobalt powder. The effect of magnetic was experimentally investigated in this study using Vibrating Sample Magnetometer (VSM). Meanwhile, the rheological properties related to the frequency and current sweep were examined using rheometer Anton Paar in the absence and presence of the magnetic field. Moreover, the magnetic properties of MRE with cobalt exhibit higher magnetic saturation up to 78.74 emu/g as compared to conventional MRE. In the meantime, the storage modulus of MRE with cobalt depicted an enhancement of field-dependent modulus at all magnetic field applied. Considering that the introduced cobalt as a filler and the obtained results are satisfactory, the introduced study might open new avenues for the cobalt to be used as filler in the MRE fabrication.