Cast iron is extensively used as the material for manufacturing disc brakes. This is much heavier and thus reduces initial acceleration and causes more fuel consumption. For reducing these effects, we use ceramic brakes.

1. CERAMIC DISC BRAKES
Presented by,
CH.DURGARAO
12671A0366

2. INTRODUCTION
 Today’s technology is in need for speed, also safety
as well, for that deceleration is needed engines of
max efficiency for maintaining the speed & brakes
of latest technology is used.
 Brake system are required to stop the vehicle within
the smallest possible distance. By converting
kinetic energy into heat energy which is dissipated
to atmosphere.
 For coping up with today’s speed, new materials
are introduced in the manufacture of brakes.

3.  In my seminar, I am introducing to you the ceramic disc
brakes. Cast iron is extensively used as the material for
manufacturing disc brakes. This is much heavier and
thus reduces initial acceleration and causes more fuel
consumption. For reducing these effects, we use
ceramic brakes.
 The ceramic disc brakes possess the following advantages:
 Its weight is half the weight of conventional disc brakes.
 It increases the fuel efficiency of the vehicle.
 It functions well in wet conditions as well.
 The major disadvantage is its cost.

4. MAIN REQUIREMNTS
 The brakes must be strong enough to stop the
vehicle within the minimum possible distance in an
emergency. But this should also be consistent with
safety. The driver must have a proper control over
the vehicle during emergency braking and the
vehicle must not skid.
 The brakes must have good antifade characteristics
and their effectiveness should not decrease with
constant prolonged application.

5. STOPPING DISTANCE OF A VEHICAL DEPENDS
 Vehicle speed
 Condition of the road surface
 Condition of tyre tread
 Coefficient of friction between the tyre tread and
the road surface
 Coefficient of friction between the brake
drum/disc and brake lining/friction pad
 Braking force applied by the driver

6. TYPES OF BRAKES
Purpose Construction Method of
actuation
Extra
braking
effort
Service
brakes
Drum brakes Mechanical
brakes
Servo brakes
Parking
brakes
Disc brakes Hydraulic
brakes
Power
operated
brake
Electric
brakes
Air brakes

7. DISC BRAKE- CONSTRUCTION

8. DISC BRAKES
 a disc brake consists of a cast iron disc bolted to
the wheel hub and a stationary housing called
caliper.
 The caliper is connected to some stationary part
of the vehicle, like the axle casing or the stub axle
and is cast in two parts, each part containing a
piston.
 In between each piston and disc there is a friction
pad held in position by retaining pins, spring plates
etc., passages are drilled in the caliper for the fluid
to enter or leave each housing. These passages
are also connected to another one for
bleeding.

9.  When the brakes are applied hydraulically actuated
pistons move the friction pads into contact with
the disc, applying equal and opposite forces the later.
 On releasing the brakes the rubber sealing rings act
as return springs and retract the pistons and the
friction pads away from the disc

10. CONSTRUCTIONAL FEATURES
 Two types brake discs are generally used the solid
type and the ventilated type. The ventilated type
more efficient since it provides better cooling. But
they are thicker and heavier than solid type, they
are liable to wrap at severe braking conditions, the
dirt accumulates in the vents which affects cooling
and apart produces wheel imbalance.
 The discs of the brakes are made of pearlite gray
cast iron. The material is cheap and has good
antiwear properties.Their main drawback is the non
uniform frictional behavior.

11.  The other materials used for the manufacture of
disc are
1. Aluminium
2. Ceramic
 Obviously, cast-iron disc is the heaviest part of a
brake - about 8 kg each, or 32 kg per car.
Aluminium alloy discs are used in the Lotus Elise.
Though light, they were less resistant to heat and
fade.
 In contrast, carbon-fiber disc is most heat-resisting
yet is by far the lightest, however, it requires very
high working temperature, and otherwise braking
power and response will be unacceptable.

12.  Ceramics are inorganic, non-metallic materials that
are processed and used at high temperatures. They
are generally hard brittle materials that withstand
compression very well but do not hold up well under
tension compared to the metals.
 They are abrasive-resistant, heat resistant and can
sustain large compressive loads even at high
temperatures. The nature of the chemical bond in
the ceramics is generally ionic in character

13. COMPARISON B/W CERAMIC DISC BRAKES AND
CONVENTIONAL DISC BRAKES
 Until now brake discs have been made up of grey
cast iron, but these are heavy which reduces
acceleration, uses more fuel and has a high
gyroscopic effect.
 Ceramic disc brake weight less than carbon/carbon
disc but have same frictional values, used in
Formula1 racing cars etc.
 CDB good at wet conditions but carbon/ carbon
disc fails in wet conditions.

14.  Weight – CDB are 61% lighter, reduces 20kg of car,
apart we can save the fuel, resulting in better
mileage. Improve the shock absorber and un-
sprung masses. We can add more safety features
instead of the current weight.

15. MANUFACTURE OF CERAMIC DISC BRAKE
 In earlier days disc brakes were made from
conventional brittle ceramic material.
 Daimler Chrysler made carbon fiber reinforced
brake discs which avoid the brittleness problem. In
the earlier days, long carbon fibers were used.
Later the use of short carbon fibers increased the
efficiency.
 short carbon fibres + carbon powder + resin
mix(at1000 DC, sintering) = stable carbon frame
work.
 This carbon fibers are in carbon matrix. Once
cooled this material can be ground like wood and
the break disk obtains its final shape.

16.  Together with silicon the ground break disk blank is
then inserted into the furnace a second time. The
pores in the carbon framework absorb the silicon
melt like a sponge; the fibers themselves remain
unaffected by this process.
 The ceramic material is created when the matrix
carbon combines with liquid silicon. This fiber
reinforced ceramic material cools over night and the
gleaming dark grey break disk is ready
 Resins : thermo plastics resins and thermo setting
resins.

17. PORSCHE CERAMIC DISC BRAKES (PCCB)
 After a long period of research and tests Porsche
has developed new high performance disc brakes,
PCCB (Porsche Ceramic Composite Brakes).
Porsche has succeeded as the first car
manufacturer in the world to develop ceramic brake
discs with involute cooling ducts for an efficient
cooling. The new brake system offers a substantial
improvement in the car braking technology.
 Instead, the Porsche Ceramic Composite Brake
ensures maximum deceleration from the start
without requiring any particular pressure on the
brake pedal. And the new brake system is just as
superior in its response under wet conditions

18. PORSCHE CERAMIC DISC BRAKES (PCCB)
 Porsche has developed
new high performance
disc brakes, (PCCB).
CDB with the involute
cooling ducts for an
efficient cooling. Offers
braking response,
fading stability, weight &
service life. Does not
require substantial
pedal forces or any
technical assistance.

19.  PCCB ensures maximum deceleration from without
any particular pressure on the brake pedal. It
response under wet condition. New braking linings
cannot absorb water. Cross drilled brake discs help
to optimize response of the brakes also in wet
weather.
 The process involves of carbon powder, resins and
carbon fibres in a furnace to about 1700DC is a
high vacuum process

20. ADVANTAGES & DISADVANTAGES
 50% lighter than metal disc brakes reduces 20kg of
car. In the case of train 36 disc brakes saving
amount to 6 tons . Apart from saving fuel also
reduce unsprung masses with a further
improvement of shock absorber response &
behavior.
 High frictional values in deceleration process
Porsche- 100 to 0 km in 3 sec.
Daewoo’s Nexia- 100 to 0 km in 4 sec.
 Brake temperature.
 Resistance up to 2000 DC.
 Still runs after 300000 km need not change CDB.

21.  No wear, maintenance free and heat and rust
resistant even under high oxygen concn.
 Heavy commercial can be braked safely over long
distance without maintenance.
 DISADVANTAGES
 High initial cost and high cost of production.
 As the advantages listed above we can hope CDB
will work out to be cheaper in the future.

22. APPLICATIONS
 FORMULA1- in mid 90’s French sports car
specialist Venturi.
 Porsche 911 turbo- with a top speed of 305 km/h
and acceleration from rest to 100 km/h in 4.2s. Its
engine 3.6 L with 420 hp max torque 560 Nm is still
running with PCCB.
 911GT2- and Mercedes Benz’s futuristic vision GST
is going to reinforce CDB .

23. CONCLUSION
 CDB due to its advantages over the conventional
brake disc are going to be the brake disc for cars in
the future. With the success of Porsche turbo car,
many other racing cars and commercial vehicles
are going to implement CDB in cars.