CERAMIC DISC BRAKESNAME-: ABHISHEK KUMAR SWARNAKAR BRANCH-: MECHANICALREGD.NO-: 1201218092SEM-: 7TH
INTRODUCTIONTodays technology is in need for speed, also safety as well, for that deceleration is needed engines of maximum 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.
MAIN REQUIREMENTSBrakes must be strong enough to stop the vehicle within the possible distance in an emergency. (safety)
Brakes should have good anti-fade characteristics also on constant prolonged application its effectiveness should not decrease.
STOPPING DISTANCE OF A VEHICAL DEPENDS Vehicle speedCondition of road surface.Condition of tyre thread.Coefficient of friction b/w tyre thread & road surface.Coefficient of friction b/w brake disc/drum & brake pad.Braking force applied by the driver.
TYPES OF BRAKESAccording to the purposeService or primary brakesParking or secondary brakesAccording to the constructionDrum brakesDisc brakesAccording to the method of actuationMechanical brakesHydraulic brakes and Air brakesElectric brakesVacuum brakesAccording to the extra braking effortServo brakes or power assisted brakesPower operated brake
TYPES OF BRAKE MATERIALSGrey cast iron discHeavy Rust formation Aluminum discLight Less resistant to heat and fadeCarbon-fiber discHeat resistantNeeds high working temperatureCeramic discInorganic and non-metallicHard and brittle materialHigh heat and abrasive resistanceCan sustain large compressive load
CERAMIC DISC BRAKES AND CONVENTIONAL DISC BRAKESGrey cast iron disc is heavy which reduces acceleration, uses more fuel.Ceramic disc brake weighs less than conventional disc brakes but have same frictional values, used in F-1 racing cars etc.CDB good at wet conditions but conventional disc fails in wet conditions. CDBs are 61% lighter, reduces 20kg of car, apart we can save the fuel, resulting in better mileage. Improve the shock absorber. We can add more safety features instead of the current weight.
MANUFACTURE OF CERAMIC DISC BRAKEIn earlier days disc brakes were made from conventional brittle ceramic material. DIAMLER CHRYSLER made carbon fibre reinforce brake disc to avoid the brittle property. Short carbon fibres + carbon powder + resin mix(at 1000c sintering) = stable carbon frame work.After cooling ground like wood brake disc obtains its shape.Add silicon to the required shape and insert in the furnace for the second time.Resins : thermo plastics resins and thermo setting resins .
COATING OF CERAMIC ON CONVENTIONAL BRAKE DISCSFRENO Ltd. used metal matrix composite for disc, an alloy of aluminum for lightness and silicon carbides for strength. The ceramic additive made the disc highly abrasive and gave a low unstable coefficient of friction.
SULZER METCO Ltd. special ceramic coating, developed thermal spray technology as well as manufacturing plasma surface.
PORSCHE CERAMIC COMPOSITE DISC BRAKES (PCCB)This is manufactured using a high vacuum process. The process involves heating carbon powder, resins and carbon fibres in a furnace at 1700 c
PROPERTIES OF PCCBCDB with the involute cooling ducts for an efficient cooling. Offers braking response, fading stability, weight & service life. PCCB ensures maximum deceleration from without any particular pressure on the brake pedal.Superior 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.
ADVANTAGES50% lighter than metal disc brakes, reduces 20kg of car. 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. Brake temperature resistance up to 2000 c .Still runs after 300000 km need not change CDB.No wear, maintenance free and heat and rust resistant even under high oxygen concentration.
High initial cost and high cost of production.
APPLICATIONSFORMULA-1 cars and sports cars
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 Benzs futuristic vision GST is going to reinforce CDB .
APPLICATION IN PORSCHE 911
CDB IN UPPER CLASS LIMOUSINES
CDB IN SPORTS CARS
CONCLUSIONCDB due to its advantages over the conventional brake discs 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.