الفهرس 
Chapter One: IntroductionOnly 14 pages are availabe for public view
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Abstract
A disc brake is a type of brake that uses calipers to squeeze pairs of pads against a disc in order to create friction that retards the rotation of a shaft. The conventional disc brake is usually made of cast iron. The main problem of cast iron is that fading phenomenon occurs faster in iron disc due to low heat dissipation. Also reducing vehicle weight is an appropriate way to save the power. Therefore, cast iron was replaced by aluminum alloys, as aluminum has a higher thermal conductivity than cast iron and is lighter in weight than it. And study its effect on the brake performance under various operating conditions such as applied pressures and wheel speed on disc brake vibration, noise, temperature and brake force.
The experimental results indicate that, the vibration and noise has been found to decrease with increases of the applied pressure and increased with increases of the wheel speed in both discs. Also found the brake force and temperature in both discs have been found to increase with increases of the applied pressure and with increases of the wheel speed. The vibrations and noise are higher in aluminum alloy disk. The rate of increase in vibration at aluminum alloy disc ranges from 11 to 16 % at 54 rpm. The increasing in noise at aluminum alloy disc ranges from 68 to 57.4 % at 54 rpm. The frictional force increased with increase applied pressure and wheel speed but the rate of increase in the aluminum alloy disc is higher than that of cast iron. Because of the frictional force in the aluminum alloy is 16.6% more than the cast iron under identical conditions. The increasing of temperature in aluminum alloy disk is more than cast iron. But the heat dissipation of the aluminum alloy disc is better than the cast iron disc because the thermal conductivity of the aluminum is higher than the cast iron. The rate of increase in temperature of aluminum alloy disc ranges from 39 to 24.7 % at 54 rpm.