DEVELOPMENT & RHEOLOGICAL CHARACTERIZATION OF ISOTROPIC & ANISOTROPIC MATERIAL

Abstract

MR (magneto rheological) are smart material that is responsive to external stimuli like magnetic field or electric fields, temperature, moisture content, stresses etc. MR materials are designed to change their rheological & viscoelastic properties by outside magnetic field. MR materials Possess a range of uses are used in mechanical device sensors, actuators, adjustable vibration absorbers & isolators for controlling seat vibration in cars etc. This is due to their unique speciality the shows a Quick reaction in real time for different magnetic field of intensities[1]. MR materials are consisting of fluids, gel, foams & elastomer and MR fluids and MRE (magneto rheological elastomers) are the two main parts. MR materials are composed of small micro size magnetic particles that are suspended in non-magnetic matrix.MR fluids ferromagnetic particles (carbonyl iron particles CIPs) are suspended in carrier fluid like silicone oil & PDMS. Here magnetic particles are suspended into fluid without magnetic field & have characteristic of low viscosity fluids[2]. But when we created magnetic fields, particles move at milliseconds speeds along with the induction line, formed magnetic force chain this transitions are quickly from low-viscosity fluid to a high viscosity. But when we remove the magnetic field, it recovers its fluid state. MR fluids have associated with critical issues such as sedimentation stability of particles, such as leaking, caking, all these are unstable due to density difference in the main components that makes it less desirable than MRE.