CN101457172B

CN101457172B - Stabilizing type magnetic rheological fluid

Info

Publication number: CN101457172B
Application number: CN2009101160327A
Authority: CN
Inventors: 江万权; 朱红; 龚兴龙
Original assignee: University of Science and Technology of China USTC
Current assignee: University of Science and Technology of China USTC
Priority date: 2009-01-09
Filing date: 2009-01-09
Publication date: 2011-11-30
Anticipated expiration: 2029-01-09
Also published as: CN101457172A

Abstract

The invention relates to a stable type magneto-rheological liquid solving the stability and redispersibility problems of the magneto-rheological liquid. The stable type magneto-rheological liquid of the invention comprises the materials as follow by volume ratio: 15-404563530f carbonyl iron powder, 0. 5-104565674f surfactants, 50-7524535440f methyl-silicone oil and 0. 5-102f additive agent, wherein the surfactants are geoceric acid or oleic acid or Tween, the additive agent is silicon oxide or bentonite. The magneto-rheological liquid prepared by the invention exhibits excellent stability and redispersibility performance. The 24h precipitation amount of the magneto-rheological liquid is less than 5, 140h precipitation amount is not more than 15 The magneto-rheological liquid does not harden when the liquid is stored for two years, and exhibits the same magneto-rheological performance as new preparation. A shearing stress of the magneto-rheological liquid can reach 25kPa when the externally-applied magnetic field is 500mT.

Description

A kind of stabilizing type magnetic rheological fluid

Technical field

The present invention relates to the intelligent material technical field, be specifically related to a kind of sedimentation stability, chemical stability and redispersion performance are good, and the relatively low magnetic flow liquid of cost.

Background technology

Magnetic flow liquid is to be dispersed in the suspension system that forms in the carrier fluid by magnetic-particle, this system can take place according to the change of externally-applied magnetic field to be converted into the reversible change of class solid state rapidly from Newtonian fuid, and follow the change of corresponding physical and chemical performance, show controllable rheological properties.Since magnetic flow liquid after at first finding by J.Rabinow the forties in 20th century, based on its controlled magnetorheological performance, this intelligent material is widely used in the engineering device in order to realize the intelligent control to vibration.With the practical devices of developing magneto-rheological vibration damper, magnetorheological brake valve, magnetic rheological clutch, MR damper, magnetorheological polisher etc. are arranged so far, application prospect is boundless.But because magnetic flow liquid is a kind of suspension system, there is bigger density difference in magnetic-particle in suspension medium in this system, thereby cause magnetic-particle sedimentation in carrier fluid, even harden, badly influence the sedimentation stability of magnetic flow liquid, chemical stability and redispersion performance, this just badly influences the stability of magnetic flow liquid in various magnetorheological devices, and limits its extensive use in the engineering apparatus.Based on this consideration, the stability and the redispersion performance that solve magnetic flow liquid are most important to the practical application of magnetic flow liquid.

Because the practicality of magnetic flow liquid is at present a lot of about the research work of magnetic flow liquid, mainly is divided into two big classes, a class is the modified magnetic particle, wraps up one deck Fe as patent 200410067824.7 in carbon nano tube surface ₃O ₄With the preparation method of a kind of magnetic composite particles at magneticmetal surface coated inorganic oxide skin of the method for preparing the magnetic composite particles and patent 200410060854.5 reports etc.; Another kind of is to add additives such as tensio-active agent, thixotropic agent, antioxidant to change the component of carrier fluid, adds in the magnetic flow liquid to improve its stability and magnetorheological performance as additive as reducing carbonyl iron and amorphous iron-base soft magnetic alloy of patent 200510134250.5 with crystalline state.

Summary of the invention

For stability and the redispersibility problem that solves magnetic flow liquid, the invention provides the stabilizing type magnetic rheological fluid that still can keep satisfactory stability and magnetorheological performance after a kind of long storage time.

Concrete technical solution is as follows:

A kind of stabilizing type magnetic rheological fluid comprises the raw material of following volume ratio:

Carbonyl iron dust: 15-40%

Tensio-active agent: 0.5-10%

Methyl-silicone oil: 50-75%

Additive: 0.5-10%;

Described tensio-active agent is stearic acid, oleic acid and tween;

Described additive is silicon oxide and wilkinite.

The consumption of described tensio-active agent is as follows:

Stearic acid dosage is 0.1-3%, and the oleic acid consumption is 0.2-3%, and the tween consumption is 0.2-4%.

The consumption of described additive is as follows:

The silicon oxide consumption is 0.25-5%, and bentonite consumption is 0.25-5%.

The tensio-active agent that adds in the present invention's prescription can form the layer protecting film thin layer on magnetic-particle carbonyl iron dust surface, plays the effect that prevents particle adhesion, reunites, hardens to a certain extent; The adding of silicon oxide has effectively improved the particulate wear resistance; Wilkinite can form network structure in this magnetic flow liquid system, effectively prevent the magnetic-particle sedimentation, and when externally-applied magnetic field makes magnetic flow liquid generation magnetic rheology effect, this network structure again can be destroyed in moment, thereby can not have influence on the magnetorheological performance of magnetic flow liquid and controlled switching characteristic thereof.Magnetic flow liquid 24h sinkability of the present invention is less than 5%, and the 140h sinkability is not more than 15%, and it was deposited more than 2 years, do not occur yet hardening, and the magnetorheological performance when showing as new system.

Description of drawings

Fig. 1 is dynamic shearing stress and shear strain rate graph of a relation,

The graph of a relation of Fig. 2 plastic viscosity and shearing rate during for no externally-applied magnetic field,

Fig. 3 is shear-stress and magneticstrength graph of a relation,

Fig. 4 is different magnetic field down cut stress and volume fraction graph of a relation,

Fig. 5 be temperature to null field viscosity influence figure,

Fig. 6 is that temperature is to dynamic shearing stress influence figure.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described by embodiment.

Embodiment 1:

Take off the raw material of row volume fraction:

Carbonyl iron dust: 15%;

Tensio-active agent: 0.5%, wherein stearic acid 0.1%, oleic acid 0.2%, tween 0.2%;

Methyl-silicone oil: 74.5%,

Additive: 10%, wherein silicon oxide 5%, wilkinite 5%.

Magnetic flow liquid formulation operations step is as follows:

(1) above-mentioned raw materials is added in the agate jar by amount, put into some agate balls, grinding than beginning under the lower velocity, the raw material that is intended to add mixes; After waiting that the raw material that is added mixes fully, add remaining raw material by amount, low speed grinds, and adds in the ball grinder until whole raw materials.

(2) add all raw materials after, keep ball mill in steady state, low speed ball milling a few hours.

(3) magnetic flow liquid in the ball grinder is taken out, clean agate ball, agate jar.

Magnetic flow liquid of the present invention is in measurement range, and shear strain rate changes less to the influence of shear-stress, and magneticstrength is big more, and shear strain rate is more little to the influence of shear-stress, sees Fig. 1; Under no externally-applied magnetic field condition, this magnetic flow liquid presents lower plastic viscosity, less than 5Pa.s, sees Fig. 2; Along with magneticstrength increases, shear-stress increases, and when magneticstrength was 500mT, shear-stress can reach 25kPa, sees Fig. 3; Along with Fe volume fraction and magneticstrength increase, shear-stress increases, and sees Fig. 4; In 10-80 ℃ of temperature range, this magnetic flow liquid initial viscosity raises with temperature and descends, and sees Fig. 5; In 10-80 ℃ of temperature range, temperature change is very little to the dynamic shearing stress influence of this magnetic flow liquid, and as seen this magnetic flow liquid all can present stable dynamic shearing stress in 10-80 ℃ of temperature range, sees Fig. 6.

The prepared magnetic flow liquid of the present invention shows splendid stability and redispersion performance.Magnetic flow liquid 24h sinkability is less than 5%, and the 140h sinkability is not more than 15%, and it was deposited more than 2 years, do not occur yet hardening, and the magnetorheological performance when showing as new system.When this magnetic flow liquid was 500mT at externally-applied magnetic field, shear-stress can reach 25kPa.

Embodiment 2:

Take off the raw material of row volume fraction:

Carbonyl iron dust: 20%;

Tensio-active agent: 1%, wherein stearic acid 0.3%, oleic acid 0.3%, tween 0.4%;

Methyl-silicone oil: 74%;

Additive: 5%, wherein silicon oxide 2.5%, wilkinite 2.5%.

Other is with embodiment 1.

Embodiment 3:

Take off the raw material of row volume fraction:

Carbonyl iron dust: 25%;

Tensio-active agent: 2%, wherein stearic acid 0.6%, oleic acid 0.6%, tween 0.8%;

Base silicone oil: 70%;

Additive: 3%, wherein silicon oxide 1.5%, wilkinite 1.5%.

Other is with embodiment 1.

Embodiment 4:

Take off the raw material of row volume fraction:

Carbonyl iron dust: 30%;

Tensio-active agent: 3%, wherein stearic acid 1%, oleic acid 1%, tween 1%;

Methyl-silicone oil: 65%;

Additive: 2%, wherein silicon oxide 1%, wilkinite 1%.

Other is with embodiment 1.

Embodiment 5:

Take off the raw material of row volume fraction:

Carbonyl iron dust: 35%;

Tensio-active agent: 5%, wherein stearic acid 1%, oleic acid 2%, tween 2%;

Methyl-silicone oil: 59%;

Additive: 1%, wherein silicon oxide 0.5%, wilkinite 0.5%.

Other is with embodiment 1.

Embodiment 6:

Take off the raw material of row volume fraction:

Carbonyl iron dust: 40%;

Tensio-active agent: 10%, wherein stearic acid 3%, oleic acid 3%, tween 4%;

Methyl-silicone oil: 49.5%;

Additive: 0.5%, wherein silicon oxide 0.25%, wilkinite 0.25%.

Other is with embodiment 1.

Claims

1. stabilizing type magnetic rheological fluid is characterized in that comprising the raw material of following volume ratio:

Carbonyl iron dust: 15-40%

Tensio-active agent: 0.5-10%

Methyl-silicone oil: 50-75%

Additive: 0.5-10%;

Described tensio-active agent is stearic acid, oleic acid and tween; Stearic acid dosage is 0.1-3%, and the oleic acid consumption is 0.2-3%, and the tween consumption is 0.2-4%;

Described additive is silicon oxide and wilkinite; The silicon oxide consumption is 0.25-5%, and bentonite consumption is 0.25-5%.