【摘要】 根据粉体颗粒与连续电介质均匀混合的介电常数混合原理和电桥电容法测介电常数的方法,提出消除空气粉末法和油液混合法测量电流变液中粉体颗粒的介电常数。消除空气粉末法扣除了通常压片法中空气空隙的影响,更能反映粉体性能。对TiO2粉、淀粉和SiO2粉等进行实测,获得了较好的测量精度。对稀土掺杂TiO2粉进行测量发现适当稀土掺杂量可以有效提高介电常数,从而获得最佳的电流变性能效果。更多还原

【Abstract】 Based on the mingling rule of dielectric constant of two-phase-even-mixed compound and Wheatstone bridge method of dielectric constant measurement, two methods have been developed. They are air-subtracted method and oil-mixed method for determining the dielectric constant of fine powder used in ER fluids as dispersant. The air-subtracted method avoids the influence of air void produced in the ordinary plate-pressed method; therefore increases precision. With the methods, several kinds of materials have been tested and satisfactory results have been achieved. In order to improve mechanic properties, the dielectric constant and conductivity of rare earth element doped TiO2 were tested and it was find that the shear stress of ER fluid increases by approximately 6 times at 0.1 RE/TiO2 mole-rate.更多还原