Design And Synthesis Of The Er Material And Performance

Electrorheological (ER) materials have caught more and more attention due to its potential applications in mechanical applications, such as robotic controlling systems, hydraulic valves and damping devices. In order to understand clearly the mechanism of the electrorheolagical effect and obtain good ER materials which are suitable in practical application, the inorganic, organic and composite materials and so on, have been studied. Considering the investigation status in ER materials, and based on the early research in our laboratory, in this paper, seven types of ER materials, TiO₂, BaTiO(C₂O₄)₂- SrTiO₃, Al₂O₃+LiI. PbTiO₃. tourmaline and composite oxides, were synthesized, their ER properties and the influence of the composition, microstructure, surface area and dielectric properties on ER effect of a material were studied by ER test, XRD, BET surface analyses and dielectric property analyses for the samples.The results show that: (1) The crystal structure type plays a predominant role in influencing the ER performance of a material. The pure TiO₂ (anatase) obtained at 250⁵50℃ has better ER effect than that (rutile) roasted above 550℃, and the ER activity falls down with increasing rutile phase. (2) The surface area and pore volume (surface area of the pores, essentially) are important factors in determining the ER effect of a particle material. When the particles share the same composition and crystal structure type, and the grains are not very small, the larger is the surface area, the better is the ER effect. (3) The dielectric loss of a material plays a more important role than its dielectric constant, in influencing the ER effect of a particle material. In a general way, the material, which has better ER property, possesses larger dielectric loss and conductivity. (4)The ER performance of a material can be enhanced by doping some metal ions which can induce the lattice distortion and defects, due to the modification in the dielectric and conduction properties of the material. (5) The ER property can vary with the kinds of doping metal ions, and the effect of doping degree of the metal ions on ER property of a material can not ignored, generally, there is a optimal value on the doping degree, and the ER activity of the material would decrease when the doping degree beyond it.