Magnetic rheological fluid containing superfine amorphous muterial

Abstract

Chemical composition (in volume úÑ) of magnetic rheology liquid of containing superfine amorphous material is as following: magnetic particle 10-50úÑ is as reduced carbonyl iron in crystalline state and iron based amorphous soft magnetic alloys; carrier liquid 45-89úÑ is poly alpha olefin with viscosity as 1-300mPa.s under room temperature; surfactant 1-5úÑ is as titanate coupler and composite aluminium-titanium coupler. In the said magnetic particle, the reduced carbonyl iron in crystalline state (90-95úÑ of the magnetic particle)is spheroidal particle with size range 1-30 micro; and iron based amorphous soft magnetic alloys (5-10úÑ of the magnetic particle)is acicular particles. Comparing prior art, the invention possesses advantages of lower viscosity coefficient in zero field, high yield stress, fine antiflooding stability and excellent magnetic performance.

Description

technical field [0001] The invention belongs to the field of intelligent materials, in particular to a magnetorheological fluid containing ultrafine amorphous materials. Background technique [0002] In the prior art, magnetorheological fluid is a suspension formed of micron-sized magnetic particles in a carrier liquid. Under the action of an external magnetic field, magnetorheological fluid can reversibly change between liquid and solid, and it is a new type of smart material. [0003] Both magnetorheological fluid and magnetic fluid are suspensions formed by dispersing magnetic particles in a suitable liquid. Many articles do not distinguish between them, but in fact there is a difference between the two. The size range of their suspended particles are different, so performance and application are not the same. [0004] Magnetic fluid, also known as magnetic liquid, is a stable colloidal system composed of nano-scale (1-10nm) magnetic particles highly dispersed in a carr...

AI Technical Summary

Problems solved by technology

However, due to the large difference between the specific gravity of the magnetic particles and the carrier liquid, the sedimentation stability of most magnetorheological fluids is poor, and the sedimentation and agglomeration of magnetic particles are prone to occur, which affects the redispersibility of the magnetorheological fluid and greatly limits The application occasions and fields of magnetorheological fluid

[0007] In order to solve the problem of sedimentation and agglomeration of magnetic particles, various surfactants are generally added, but in fact, adding too much surfactant will not only greatly increase the zero-field viscosity of the magnetorheological fluid, but also if an inappropriate surface The active agent also tends to form rigid plates that are difficult to redisperse after the magnetic particles settle

Another method is to add non-magnetic light materials to the magnetic material to make composite particles with lighter specific gravity to improve the sedimentation stability of the magnetorheological fluid, for example: Chinese patent CN 1595558A published on March 16, 2005 " A Magneto-Rheological Fluid and Its Preparation Method" uses magnetic particles coated with silicon oxide and aluminum oxide on the surface. Although the stability of the magnetorheological fluid is improved to a certain extent, due to the introduction of non-magnetic materials , resulting in a decrease in the magnetic properties of the composite particles, and a decrease in the yield strength of the prepared magnetorheological fluid

In addition, in the Chinese patent CN 1560209A "guar gum magnetorheological fluid" disclosed on January 5, 2005, in the existing magnetorheological fluid technology, guar gum powder is used as a sedimentation stabilizer. Guar gum powder is harmless to the environment and can improve the stability of magnetorheological fluid and prevent caking. However, since guar gum is added in the form of powder, it increases the viscosity of the system to a certain extent.