Coated Rotor and Slotted Pad in a Good Interactions

Coating is very important in some applications particularly disc brakes that are most commonly used in the passenger cars. Slotted friction material also has a great effect on the behaviour of the disc brake friction. Mixing between the coated rotor and the slotted material is of importance to improve the frictional behaviour of the disc brake. Slotted material used in this work is divided into two parts; each part has leading and trailing edge to give the advantages of using two pads in a single braking action. Simulating the kinetic energy of a passenger car to measure the friction force between the disc and pad at different operating conditions have been designed in a test rig. The effect of thermal loading at the sliding interface between the different friction material and the rotor of Floating Calliper Disc Brake (FCDB) has been studied in this work. Initial disc surface temperature was measured and controlled through a high quality technique by using a thermal camera that was fixed at suitable place close to the rotor. The signal from the transducer was amplified and displayed on a digital storage oscilloscope and then fed to a computer for the final analysis. The results showed the different values of coefficient of friction depending on the different operating conditions. The maximum coefficient of friction was 0.58 that was recorded at initial disc surface temperature of 150°C while the braking pressure was 20 bar. The minimum value for the friction coefficient 0.30 was also recorded at initial disc surface temperature of 50°C at rotating speed 500 rpm while the braking pressure was 25 bar.