[DESIGN, DEVELOPMENT AND ANALYSIS OF RIM BASED MOTORCYCLE FRONT BRAKING SYSTEM]

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Acknowledgement

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible (J, 2001,, 1272).

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University (J, 2001,, 1272).

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ABSTRACT

Carbon fiber-reinforced silicon carbide matrix composites have the potential to overcome the shortcoming of the currently used carbon/carbon friction materials in aircraft brakes. In this article, the carbon/silicon carbide (C/SiC) composites were prepared by chemical vapor infiltration method, and the brake disks with different densities and component content were finally obtained. The friction coefficient and friction stability can be significantly improved by increasing both material density and carbon content. When the density of C/SiC composite is 2.3 g/cm3, the coefficient of friction measured is 0.23, the coefficient of friction stability remains about 0.43, the liner wear rate is less than 9.3 µm/cycle, and the weight wear rate is less than 9.1 µm/cycle. The rapid increase of friction coefficient approaching the end of braking is mainly related to the increasing of surface temperature in a short time and the enhanced adhesion and abrasion of contact conjunctions and asperities. The C/SiC composites exhibited a good stability of braking against fading versus the braking number and surface temperature. The surfaces of C/SiC brake disks were covered with wear debris including the fragment of carbon fibers after the braking tests. The wear on the surfaces is significantly determined by cyclic mechanical and thermal stresses, which result in the micro-cracks in the SiC matrix, the thin flakes of the surface materials as well as the grooves.

DESIGN, DEVELOPMENT AND ANALYSIS OF RIM BASED MOTORCYCLE FRONT BRAKING SYSTEM

Introduction

Carbon/carbon (C/C) composites and metallic friction pads or rings are the most common friction materials used presently. Powder metallurgy friction materials, however, cannot meet the needs of high speed and high load because of the high weight and the adhesion at high temperature.1 C/C composites yield a significant reduction of weight, high performance, and long lifetime. However, the oxidation of the fiber as well as the matrix above 400°C and the instability of coefficient of friction caused by humidity and temperature could potentially lead to brake failure and could therefore limit their service life. Furthermore, the long manufacturing period and the high cost of C/C brakes limit their further development and application.2-5 Carbon fiber reinforced silicon carbide composites (C/C-SiC), fabricated by the reaction melt infiltration (RMI) method, show some excellent advantages such as moderate density (about 2.0 g/cm3), low open porosity (<5%), and good oxidation resistance in comparison with C/C composites. In addition, the higher and more stable coefficient of friction, the insensibility to the surroundings and the smaller stack volume suggest a promising future of C/C-SiC composites ...