1. By Phillip Holifield and Nick Weil SRJC, Engr 45, Fall 2009 Semester

2.  Disk brakes convert kinetic energy from the car into thermal energy by friction

3.  The brake fluid compresses the piston inside the brake caliper applying pressure to the brake pads

4.  Connected to the axel – rotating at the same speed as the wheel  Generally made out of steel  Commonly slotted or drilled for extra heat dissipation

5.  Fixed in the brake caliper  Various compounds of materials are used  Wear over time and must be replaced

6.  Increase pad and rotor life  Reduce brake noise  Cooling to prevent heat fade  Maximize braking force  Federal Safety Requirements  Environmental Impact

7.  Passenger Cars: ◦ Low noise and wear  Trucks and SUV’s: ◦ Heavier weight requires better braking  High Performance Cars: ◦ Need maximum braking and cooling

8.  Asbestos  Semi-Metallic  Non-Asbestos Organics  Low Steel  Carbon  Exact composition of each manufacturer’s pads is a closely guarded secret

10.  Widely used in early disk brake applications  Good for absorbing and dissipating heat  Average stopping power  Asbestos is legally regulate due to it’s carcinogenic properties  No longer used due to health risks

11.  Range from 30% to 65% metal and filler  Different pads use Steel, Iron, and Copper  Harder material is very durable and has excellent heat resistance  Creates more noise and dust  Used in most cars and SUV’s

12.  Low to medium coefficient of friction ~ 0.28 –0.38  Relatively high mu variation (temperature, duty cycle)  Good fade characteristics  Poor wear at low temps., <100C  Excellent wear at temps. over 200C  Good wear under heavy loads  Poor wear at high speeds  Generally inferior Noise, Vibration & Harshness compared to NAOs  Contains no copper  Low initial cost  High fluid temperatures can be an issue

13.  Typically contain nonferrous metals, inorganic and organic fibers, abrasives, lubricants and property modifiers such as glass, rubber, kevlar and carbon  Typically used in high performance cars  Also referred to as “ceramics”

14.  Low to medium-high coefficient of friction ~ 0.33 –0.40.  Excellent wear at lower temps. < 200C.  Good for wheel dust.  Relatively poor wear under heavy duty conditions and at higher friction levels.  Good noise & roughness characteristics  Can have morning effectiveness noise – squealing noise on first couple of brake applies in the morning  More expensive.

15.  Typically contain ferrous and nonferrous metals, inorganic and organic fibers, aggressive abrasives, lots of carbonaceous and sulfide lubricants  Replacing semi-metallic as the standard for passenger cars

16.  Higher coefficient of friction levels ~ 0.38 – 0.50  Good pedal feel and braking confidence  Good fade and high speed performance  High pad/rotor wear  Good for high speed wear  Lots of wheel dust  Inferior noise and life.

17.  Composite materials reinforced with carbon fibers  Used for both pads and rotors  Used in Formula 1 and other race cars  Major manufacturers include Hitco, Brembo and Carbon Industries

18.  Light weight – rotors weigh less than 1kg  High coefficient of friction - can decelerate an F1 car at over 5G  Operating temperature is around 800-1000°C  Extremely expensive to produce

19.  Text:  http://en.wikipedia.org/wiki/Brake_pads http://en.wikipedia.org/wiki/Brake_pads  http://en.wikipedia.org/wiki/Disk_brake http://en.wikipedia.org/wiki/Disk_brake  http://auto.howstuffworks.com/auto-parts/brakes/brake-types/disc- brake.htm http://auto.howstuffworks.com/auto-parts/brakes/brake-types/disc- brake.htm  www.suscon.org/bpp/pdfs/OEBrakePads.pdf www.suscon.org/bpp/pdfs/OEBrakePads.pdf  http://www.performancefriction.com/pages/pad_type.htm http://www.performancefriction.com/pages/pad_type.htm  http://www.f1technical.net/articles/2 http://www.f1technical.net/articles/2  Images:  http://stmarysjin.org.uk/hsw/gif/disc-brake3.jpg http://stmarysjin.org.uk/hsw/gif/disc-brake3.jpg  http://www.akebonobrakes.com/oem/brake_products/images/3d_explo ded_caliper.gif http://www.akebonobrakes.com/oem/brake_products/images/3d_explo ded_caliper.gif  https://www.nzad.co.nz/store/images/standard%20brake%20rotor%20(S mall).jpg https://www.nzad.co.nz/store/images/standard%20brake%20rotor%20(S mall).jpg  http://www.good-win-racing.com/miata/images/items/GWR-078.jpg http://www.good-win-racing.com/miata/images/items/GWR-078.jpg