Evaluation of C/C-SiC Composites as Potential Candidate Materials for High Performance Braking Systems

Abstract

Abstract. This paper is aimed at evaluating the characteristic and performance of C/C-SiC composites as potential candidate materials for high performance braking system. A set of material specifications had been derived from specific engineering design requirements. Analysis was performed by formulating the function(s), constraint(s), and objective(s) of design and materials selection. Function of a friction material is chiefly to provide friction, absorb and dissipate energy. It is done while withstanding load and maintaining the structural adequacy and characteristic of tribology at high temperature. Objective of the material selection and design is to maximize the absorption and dissipation of energy and to minimize weight and cost. Candidate materials were evaluated based on their friction and wear, thermal capacity and conductivity, structural properties, manufacturing properties, and densities. The present paper provides a state of the art example on how materials -function -geometry -design, are all interrelated. IntroductionBraking system is one of the most important parts in mechanical design. Challenging engineering design requirements along with such other critical issues as safety, liability, health, environment, and energy, has driven the development of new friction materials. On the other hand, the discovery of friction materials, which is also pushed by science and technology, has promoted the development friction system design. The development of friction materials is strongly related to the design and applications.One of the major applications of friction materials is in transportation vehicles. Development of advanced friction materials was essentially 'pulled' by the need of aerospace and military industries that are considered as the frontiers in advanced technology. Carbon/Carbon composites, which were attributed to Brennan Forcht of Chance Vought Aircraft, were initially developed in 1958 to respond the need of US space and defense industries [1]. Carbon/Carbon composites, which were particularly developed to meet a set of material specifications dictated by specific design objectives, then had become one of the important friction materials for lightweight and high performance applications.Use of Carbon/Carbon composite materials in commercial passenger aircraft braking systems dates back to 1973 when the materials, which were provided by Dunlop, went to the first trial on VC10 aircraft before becoming a standard attachment on supersonic passenger aircraft Concorde in 1974 [1,2]. The technology, which is formerly directed to advanced applications, has been recently adopted and developed for a wider range of engineering applications. By the end of the 21th century, about 60% volume of Carbon/Carbon composites had been used in Aircraft Braking System in more than 50 types of aircrafts [1]. Recently, the materials have become the prime choice for aircrafts and other high performance braking systems involving military aircrafts, commercial aircrafts, and racing cars [1][2][3][4].