The investigation of the compression and tension behavior of the cobalt ferrite magnetorheological fluids synthesized by co-precipitation

This paper aims at studying the effect of the particle size on the compression and tension behavior of the cobalt ferrite-based magnetorheological fluid (MRF). To achieve this goal, Co-ferrite nano-particles (CoFe2O4) with three different sizes, were synthesized by the chemical co-precipitation method and then two of them were mixed together. The X-Ray Diffraction (XRD) analysis, Scattering Electron Microscope (SEM), Laser Particle Size Analysis (LPSA) and Vibrating Sample Magnetometer (VSM) were carried out to study the phase analysis, particles morphology, particle distribution and magnetic properties, respectively. Then the compression and tension tests were conducted on MRFs containing silicon oil as a carrier. The results showed that the highest values of the compression and tension strengths of fluids correspond to the larger particle sizes (550 nm) with 1.241 and 0.594 MPa, respectively. Furthermore, the compression and tension strengths of the mixed one (1.153 and 0.388 MPa) containing 60 and 300 nm samples are higher than its components with 0.431 and 0.249 MPa, as well as 0.694 and 0.367 MPa, respectively.