Papers by Author: Hong Zhao

Abstract: This paper emphasis has researched the effect of particles scattering, surrounding thickness, heat treatment temperature and etc on microstructure, mechanics properties and macrostructure under different electric field of Ni/TiO₂, Ni/TiO₂/PAn Particles ER fluid, It is found that particles scattering, surrounding thickness, heat treatment temperature have major effect on shear stress and chain of particles.

Abstract: By means of mechanical properties test，the relationship among shear ratio, concentration and electric field, magnetic field, electromagnetic field on the Ni/TiO2/SDBS EMR fluid properties have been analyzed. It had found that with increasing shear ratio，the shear stress of Ni/TiO2/SDBS EMR fluid increased for same composition, but there is a critical value. With increasing concentration，the property of EMR fluid increased for same shear ratio. Coupling electromagnetic field makes the properties improve.

Abstract: By means of mechanical properties test，the relationship among shear ratio, concentration and electric field, magnetic field ,electromagnetic field on the Ni/TiO2 group electrorheological fluid properties have been analyzed. It is found that with increasing shear ratio，the property of electrorheological fluid increased for same composition ER, but there is a critical value. With increasing concentration，the property of electrorheological fluid increased for same shear ratio. Coupling electromagnetic field makes the properties improve.

Abstract: By means of mechanical properties test and microstructure graph observation，the relationship of heat treatment temperature of core-shell Ni/TiO2 group particles with mechanical properties under different electric field has been researched .It is found that the FT-IR，XRD morphology of heat treatment at350°C is different from the one at100°C，the shear stress of same composition ER decreased with heat treatment temperature increasing. But the leakage current density of ER shows contrary result. That is because the leakage current density of ER decreased with the increasing heat treatment temperature.

Abstract: NiTi alloys are widely used for bone implants due to their good mechanical properties. However, they can suffer certain disadvantages, such as leaching of toxic nickel ions and poor osteoinductive properties. A porous (Ca, P)-doped TiO2 /dense Ti double coatings on NiTi alloy with porous (Ca, P)-doped TiO2 coating as the top layer and a dense Ti coating as the interlayer should possess a very good combination of bioactivity and chemical stability. In this paper, the double coatings were formed by applying a duplex process of arc ion plating (AIP) and micro-arc oxidation (MAO). X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) have been used to investigate the microstructure and morphology of the coatings.

Abstract: Electrorheological (ER) fluids are regarded as smart materials with potential for application in various industries because of the controllable viscosity, the reversibly and fast response. In this paper, core-shell structured Ni/Ti/Urea nanoparticles, as an ER material, were prepared by a sol-gel method. TEM, XRD and FT-IR spectra demonstrated that the Ni nanoparticles have been homogeneously coated with a 2 nm thick layer of TiO2 containing polar groups. The polar groups were caused by the introduction of urea. The ER effect of the fluids of Ni/Ti/Urea particles in silicone oil was investigated under a DC electric field. It is found that the ER fluids of the urea-doped Ni/TiO2/Urea particles have a high ER activity, which is 10 times that of the particles containing no urea. The polar groups in the particles are the intrinsic reasons for the enhancement of electrorheological effect.

Abstract: By means of mechanical properties test and microstructure graph observation，the effect of core-shell Ni/TiO2 particles size, concentration on the properties and morphology of electrorheological fluid was emphatically studied, It is found that with concentration increasing the properties of electrorheological fluid can be improved, but there is a critical value, Urea content of Ni/TiO2 particles is 30%, in the same field with increasing concentration, particles chain of electrorheological fluid become strong，coarse and interweaved each other. The smaller of particle size, the higher of shear strength of electrorheological fluid.