title: Study of the effect of particle volume fraction on the microstructure of magnetorheological fluids using ultrasound: Transition between the strong-link to the weak-link regimes.
abstract: The effect of particle volume fraction on the microstructure of magnetorheological (MR) fluids has been studied using ultrasonic techniques. When no magnetic field is applied, they behave as slurry. However, when magnetic field is applied, important features regarding the change of the microstructure have been found with the help of ultrasonic waves propagating in the direction of the magnetic field. As the volume fraction increases, a rearrangement of particles which decrease the compressibility of the system is detected; nevertheless, the material behaves as a non-consolidated material. Three different particle volume fraction regions are found identifying a critical particle volume fraction predicted in the literature. Ultrasounds are confirmed as an interesting tool to study MR fluids in static conditions.
authors.affiliation: Institute of Physical and Information Technologies, CSIC, 28006 Madrid, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Rodríguez-López
authors.affiliation: Institute of Physical and Information Technologies, CSIC, 28006 Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Castro
authors.affiliation: Institute of Physical and Information Technologies, CSIC, 28006 Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Elvira
authors.affiliation: Institute of Physical and Information Technologies, CSIC, 28006 Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Montero de Espinosa
keywords: Magnetic field; Magnetorheological fluids; Strong-link regimen; Ultrasonic characterization; Weak-link regimen