40results about How to "Enhance the magnetorheological effect" patented technology

The magnetic rheologic liquid is composed of components: chelation type surfactant / carbonyl iron hull type magnetic compound particles, and silicone oil based compound assorted carrier liquid prepared from silicone oil and additive. The additive includes thixotropic agent, antioxidant, antiwear additive, and surfactant. The method for preparing the liquid includes steps: mixing round surfactant being added to silicone oil; next, adding antioxidant, thixotropic agent, and antiwear agent, then mixing them to obtain silicone oil based compound assorted carrier liquid; adding magnetic compound particles to the carrier liquid, and after procedures of mixing, ballmilling, and separating out friction balls, then sealing the liquid inside plastic bottle; stable silicone oil based magnetic rheologic liquid is obtained after series of procedure: placing the plastic bottle in magnetic field, taking out the liquid, and mixing etc. The liquid is applicable to damper, variator for cars etc.

The invention relates to suspended particles for water-based magnetorheological fluids and a manufacturing method thereof. The magnetic particle wrapped by hydrophilic polymer, the surface of the magnetic metal is coated with an inorganic oxide layer, which is characterized in that: the inorganic oxide layer is coated with a hydrophilic polymer layer with an alkoxy silicon at the end. Its preparation method, according to the ratio of substances, 100 parts of magnetic metal composite particles coated with inorganic oxides on the surface, 0.1 to 5.0 parts of alkoxy metal compound, and a hydrophilic polymer with an alkoxy silicon at the end 0.05 to 5.0 parts are fully dispersed in 50-10000 parts of N,N-dimethylformamide solvent, while stirring, add lye dropwise to adjust the pH value of the system, use magnetic separation and water washing to purify and collect the solid, and dry After obtaining the product. The invention has good oxidation resistance and excellent soft magnetic properties, and its preparation method is convenient and easy.

The invention discloses a magneto-rheological elastomer capable of accurately controlling axial distribution of magnetic particles and a preparation method thereof. The method comprises the steps that: firstly, according to the magneto-rheological effect change requirement of a target magneto-rheological elastomer in a certain axial direction, the target magneto-rheological elastomer is divided into a plurality of sections of magneto-rheological effect monomers according to a certain division sequence, the magneto-rheological effect monomers are prefabricated, and each section of the magneto-rheological effect monomers has the mass fraction occupied by a specific magnetic particle; and stacking the prefabricated magneto-rheological effect monomers in a final shaping mold consistent with the three-dimensional model in shape in sequence, and heating, pressurizing and forming the combined body to obtain the target magneto-rheological elastomer. According to the magneto-rheological elastomer prepared by the invention, the content of the magnetic particles in each magneto-rheological effect monomer is accurately controlled, so that the magneto-rheological effect generated by the magneto-rheological effect monomer generates gradient distribution in the axial direction, and the requirement of serving as a medium for forming a complex curved surface metal component by pressure is met.

The invention discloses a phase change type magnetorheological material and a preparation method thereof. The phase change type magnetorheological material comprises the following materials in part by mass: 38.2-69.1 parts of base materials, 30-60 parts of magnetic particles and 0.9-1.8 parts of surfactant. The base materials comprise paraffin wax and albolene, and the mass ratio of the paraffin wax to the albolene is 1.5:1-1:1.5. The magnetic particles are carbonyl iron powder. The phase change type magnetorheological material has a high magneto-induced effect and high stability, has the physical property of non-solvent type magnetorheological elastomer at room temperature, is converted into a fluid state from a viscoplastic state at high temperature (about 50 DEG C) due to the phase change performance of the base materials, and has typical characteristics of magnetorheogical fluid, namely, the phase change type magnetorheological material can be freely converted from magnetorheogical fluid to magnetorheogical elastomer or from the magnetorheogical elastomer to the magnetorheogical fluid along temperature change.

The invention relates to the field of intelligent magnetic materials and in particular relates to a graphene @Fe3O4 compound water base magnetorheological fluid and a preparation method thereof, solving the problems that existing magnetorheological fluids are easy to settle and the stability and magnetorheological effects of the magnetorheological fluids are difficult to optimize at the same time. The preparation method comprises the following steps: preparing a Fe3O4 water base magnetic fluid with FeCl2.4H2O and FeCl3.6H2O; sequentially adding concentrated sulfuric acid, potassium permanganate and hydrogen peroxide to natural flake graphite and sodium nitrate to prepare graphite oxide; and then carrying out ultrasonic dispersion on home-made graphite oxide to prepare graphene oxide, finally adding a surfactant, the Fe3O4 water base magnetic fluid and a reducing agent to graphene oxide, washing the solution with deionized water until the solution is neutral, and then dispersing graphene @Fe3O4 compound magnetic particles in the deionized water to undergo ultrasonic dispersion, removing the precipitates and taking the supernatant, namely the stable graphene @Fe3O4 compound water base magnetorheological fluid, wherein the magnetic particles are graphene @Fe3O4 and account for 5-35wt% of the whole. The method has the advantages of good stability, low zero field viscosity, high shear strain and wide operating temperature range.