Magnetorheological fluids are liquids that can change from liquid to solid when exposed to a magnetic field. They consist of magnetizable particles suspended in a carrier fluid like oil or water. As a magnetic field is applied, the particles form chains and structures that increase the fluid's viscosity and yield stress. MR fluids have applications in vehicle suspension dampers and transmissions where they allow precise control and fast response times to dampen vibrations or control torque transmission. Their properties can be controlled electronically and they require low power levels compared to similar smart fluids.

1. Magnetorheological Fluids

2. Functions of MR Fluids
 These are liquids that change their properties
when we apply a magnetic field to them.
 When the magnet is in place the MR Fluid
turns into solid.
 When the magnet is removed the solid
instantly reverts to liquid

3. What is MR fluid?
 Soft magnetic material in a carrier oil.
 Silicon oil or even corn syrup is mixed with the MRF to
prevent rust.
 Typical MR fluid contains 20-40% by volume of
relatively pure, soft iron particles.
 Rheology or to the phenomena of flowing matter
 Is type of rheological fluids whose yield stress can
be varied by an applied magnetic field.
 A typical MR fluid consists of micron sized
magnetizable iron/ferrous particles suspended in a
base fluid like silicone oil or water.

4. Applications of MR Fluid
 Vehicle Suspension
Dampers
 The MR damper has a built-
in MR valve across which
the MR fluid is forced. The
piston of the MR damper
acts as an electromagnet with
the required number of coils
to produce the appropriate
magnetic field. Also the MR
damper has a run-through
shaft to avoid an
accumulator.

5. Cont’ Applications
 MR Transmission Clutches
 They are used in automotive
power train to transmit torque
from the engine to the
transmission and the vehicle.
The MR sponge clutch may be
used to provide launch control of
an automobile thereby achieving
smooth vehicle launch.
The MRF clutch thus may
replace the existing torque
converters and therefore help
increase the fuel economy.

6. Advantages Of MR Fluid
 Easy to control
 As magnetic fields can be precisely controlled by
current driven electromagnets
 Have higher magnitude of yield stress
 Compared to ER fluids the simple construction of
devices, low power requirements for control, fast
response

7. Advantages Of MR Fluid
 Easy to control
 As magnetic fields can be precisely controlled by
current driven electromagnets
 Have higher magnitude of yield stress
 Compared to ER fluids the simple construction of
devices, low power requirements for control, fast
response