A kind of high temperature resistant magnetorheological fluid and preparation method thereof

Abstract

The invention belongs to the field of intelligent materials, and particularly relates to high-temperature-resistant magnetorheological fluid and a preparation method thereof. The magnetorheological fluid comprises the following components by weight percent: 10 to 40 percent of high-temperature heat conduction oil-base fluid, 50 to 85 percent of sulfonated polystyrene modified micro magnetic particles, 0.5 to 10 percent of nano magnetic particles, 0.1 to 10 percent of sulfonated polystyrene and 0.1 to 5 percent of additives. The high-temperature heat conduction oil resisting high temperature is used as basic fluid, and a macro-molecular compound is grafted to the surface of the magnetic particle by adopting a surface modification method, so that the compatibility between the magnetic particles and the base fluid and the settling stability of the magnetic particles in the base fluid are effectively improved, and the high-temperature-resistant magnetorheological fluid has good heat stability, settling stability and magnetorheological performance and is applicable to the fields such as spaceflights, cars, machinery, civil construction structures, precision processing, health care and the like.

Description

technical field [0001] The invention belongs to the field of intelligent materials, and in particular relates to a magnetorheological fluid suitable for vehicle vibration reduction, transmission and braking stability, high temperature resistance and a preparation method thereof. Background technique [0002] Magnetorheological Fluids (MRF) is a new type of smart material. It is a stable suspension formed by dispersing easily magnetizable particles (micron size) in the base liquid. Its physical and rheological properties change with the external magnetic field, showing continuous, rapid, reversible, precise and controllable excellent characteristics. Magnetorheological fluid devices are being widely used in the automotive industry, aerospace, machinery manufacturing, civil engineering, medical and other industries. When magnetorheological fluid devices are used to prevent earthquakes in civil engineering, settlement stability is one of the key factors for magnetorheological ...

AI Technical Summary

Problems solved by technology

When magnetorheological fluid devices are used to prevent earthquakes in civil engineering, settlement stability is one of the key factors for magnetorheological fluids; when magnetorheological fluid devices are used for automobile vibration reduction, clutches, and brakes, due to The device must be in the working state for a long time, so the long-term charging of the electromagnetic coil in the magnetorheological fluid device will generate a large amount of heat and transfer it to the magnetorheological fluid, resulting in an increase in the temperature of the magnetorheological fluid; similarly, when the magnetorheological fluid device is working , the friction between the magnetorheological fluid and the device wall and moving parts, and the friction between the magnetic particles will also generate a lot of heat, which will also cause the temperature of the magnetorheological fluid to rise

For the existing magnetorheological fluids, the increase in temperature will lead to a sharp drop in the yield stress, seriously affecting the normal operation of magnetorheological fluid devices, and also causing great difficulties in the control of magnetorheological fluid devices. In severe cases, It will cause the failure of the magnetorheological fluid device

The problem that the yield stress of magnetorheological fluid decreases due to temperature rise seriously restricts the engineering application of magnetorheological fluid in many fields, such as magnetorheological fluid brakes and magnetorheological fluid clutches in the automotive field; if it can be effectively improved The degree of heat resistance of magnetorheological fluids, solving the problem of greatly reducing the yield stress of magnetorheological fluids due to temperature rise, will greatly broaden the scope of application of magnetorheological fluids

[0003] At present, the base fluids used in the preparation of magnetorheological fluids are silicone oil, ethylene glycol, mineral oil, water, etc. As the temperature rises, the volatility and expansion rate of these base fluids will increase, resulting in the composition of magnetorheological fluids The most direct result is that the yield stress drops sharply, the stability of the magnetorheological fluid decreases, and the working effect of the magnetorheological fluid device decreases, which may seriously cause the failure of the magnetorheological fluid device

If the base fluid is water, the working temperature of the water-based magnetorheological fluid can only be within the range of 0°C to 100°C. In fact, the working temperature should be controlled within the range of 0°C to 70°C; the commonly used base liquid dimethyl Silicone oil has a boiling point of 135-220°C and a flash point of 155-300°C. As the temperature rises, especially when the temperature is higher than 100°C, small molecules will decompose, generate gas phase, volume expansion and other problems, resulting in magnetorheology The yield stress of the fluid changes irregularly, which seriously affects the rheological characteristics of the magnetorheological fluid and the exertion and control of the magnetorheological effect, and even damages the magnetorheological device, resulting in its complete failure. Therefore, the maximum working temperature of the silicone oil-based magnetorheological fluid is only Can be used at 100~130℃

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