| The development of the automotive industry make convenience for our daily life,meanwhile make the car brake manufacturing industry to flourish.Friction material as a key material in brakes,must have a safe and reliable,long life,comfortable,stable performance and no noise of friction characteristics.At present,parts of the United States issued new regulations to limite the use of copper in the friction materials,new regulations urgently need to study the development of high performance low-metal and copper-free ceramic organic friction materials.This paper aims to through the optimization of the friction materials to develop the low-metal and copper-free ceramic organic friction materials with excellent performance.The relationship between the microstructure and friction coefficient of friction films and the mechanism of synergistic action between antifriction and friction components were studied.The main research contents and methods of this paper includes the following four aspects:(1)Through inorganic and organic analysis,the chemical composition and microstructure characteristics of traditional friction materials were studied,which providing references for the component design of low-metal and copper-free ceramic organic friction materials;(2)The low-metal ceramic organic friction materials with excellent performance were prepared by optimizing the composition of friction materials,and the causes of wear problems were explained;(3)Through the optimization of friction material components,and established the AK-master dyno testing experiment grey correlation evaluation standard,and evaluated the comprehensive friction properties of friction materials,selected excellent comprehensive performance of copper-free ceramic organic friction materials.Through the tape transfer method to simplify the collecting process of the dyno testing formed friction films and wear particles under different braking initial speed and pressure,and the friction films and wear particles of microstructure,chemical composition and friction performance were studied,which explained friction and wear mechanism of the copper-free friction materials;(4)X-ray and ultraviolet photoelectron spectroscopies(XPS and UPS)et al.were performed to explain the intrinsic synergistic effect of the excellent properties of the friction and anti-friction dual characteristic ceramic friction materials.The relationship between the microstructure,electronic structure and chemical composition and hardness,corrosion,friction performance was studied.The conclusions as following:(1)The component information of different types of traditional friction materials were obtained;(2)Low-metal ceramic organic friction materials with low copper content and meeting the requirements of TL110 standard discrete band were prepared;(3)Copper-free ceramic organic friction materials with stable friction coefficient,low wear,friendly to brake disc and low noise were prepared;(4)The characteristics of dual composite ceramic friction material components in friction properties and hardness,density of charge transfer and quantified by XPS C1 s interface,found that the composite ceramic friction material had good corrosion resistance,mainly because it had larger work function and lower density of the charge transfer. |
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