Zoya Novikova

On damping vibrations of three-layered beam containing magnetorheological elastomer

In this article, we present the results of investigations of viscoelastic properties of magnetorheological elastomer containing carbonyl iron particles. Frequencies of natural vibrations of three-layered beam, supporting constructions of which are made from aluminum, and the inner layer—from magnetorheological elastomer—are calculated, and the dependence of vibrations on induction of the applied magnetic field is obtained. Nonstationary vibrations of the beam at pulse impact of magnetic field are found.

The effect of the synthesis conditions of aluminum-modified nanosized titanium dioxide on the efficiency of its use in electrorheological dispersions

A comparative study of the physicochemical properties of nanodispersed TiO2 samples synthesized from TiCl4 by the sol–gel and coprecipitation methods has shown the advantages of the former from the points of view of both the specific surface area and electrorheological response of the obtained filler in 5% electrorheological dispersions. A correlation has been revealed between the temperature of TiO2 treatment (600–800°C) and its structure, phase state and electrorheological response. The maximum shear stress increment has been observed for dispersions of TiO2 samples that contain 7–10 mol % Al and have been thermotreated at 700°C for 3.0–3.5 h.

Acoustical properties of magnetorheological fluids under applied magnetic field

This work is devoted to the experimental study of acoustical properties of magnetorheological fluids subjected to magnetic field. Evaluation of the change in velocity of ultrasonic waves and attenuation coefficients in magnetorheological fluids based on synthetic oil and carbonyl iron versus magnitude and angle φ between wave vector and intensity direction of applied magnetic field has been carried out by pulse-phase method at 1.52 and 2.5 MHz. It was found that the anisotropy of attenuation coefficient was ~5–6 dB/cm and the velocity of ultrasonic waves was up to ~1%−2% that is much more than in specimens of colloid solutions—magnetic fluids with the same dispersive phase content.

Synergistic effect in magnetoelectrorheological fluids with a complex dispersed phase

In this article, the results of investigation of structural interactions, generated by simultaneous impact of electric and magnetic fields on fluids containing a two-component dispersed phase, are presented. Dielectric, magnetic, and rheological characteristics of these fluids are considered. The characteristic features of the formed structures depending on the filler type, deformation conditions, and intensity of application of external fields are discussed.

Physicochemical and electrorheological properties of titanium dioxide modified with metal oxides

The properties of electrorheological fluids containing dispersed phase of titanium dioxide nanoparticles prepared via the sol-gel method and modified with metal oxides have been studied. Titanium dioxide has the anatase structure with crystallite sizes of 8–10 nm and a specific surface area of 90–140 m2/g. It has been found that the magnitude of the electrorheological response of the filler is determined by the specific surface area and the content of a modifying component. The strongest electrorheological response has been revealed for titanium dioxide modified with aluminum oxide at an Al content of 6.5–7.0 mol % relative to TiO2.

Influence of flowing parameter of magnetorheological polishing fluids (MRPFs) on the quality of processing polycrystalline glass ceramics

The study of rheological characteristics for two types of magnetorheological polishing fluids (MRPFs), MRPF-1 based on cerium oxide abrasive particles and MRPF-2 based on nano-diamond abrasive particles, was carried out. Experiments on polishing of a polycrystalline sitall laser mirror substrates with these fluids using magnetorheological finishing process were executed. The surface structure of the samples after the polishing was investigated with the atomic force microscope. The results of surface measurements for the samples under the study polished with both MRPF-1 and MRPF-2 fluids are reported in comparison with the existed data obtained from a regular pitch polishing method. The lowest root-mean-square roughness of 0.2–0.4 nm was obtained for the samples polished with MRPF-2.

Time stability studies of electrorheological response of dispersions with different types of charge carriers

The behavior of hydrous and anhydrous fillers of various types in the electric field is investigated. Rheological and dielectric properties of dispersions containing 20 wt% of the filler in the insulating oil are determined. The comparative results of the experimental determination of the change in shear stress and current density over time at the impact of the electric field of different intensity are presented.