Hodnocení vlastností keramických mixů pro brzdové systémy

Abstract

The construction and used frictional materials are important factors for proper function of brake system. These factors have to absorb significant part of vehicle kinetic and thermal energy during deceleration or stopping. Friction materials in brake systems are very heterogeneous composite composed of up to 20 components. Nowadays, friction materials are divided into three main groups – metallic, carbonic and based on organic resins. Master´s thesis is focused on ceramic brake pads based on organic resins (NAO mix), whose friction components are divided into four main groups – pastes, reinforcing materials, friction modifiers and fillers. All components in the brake pad are bonded by the phenol-formaldehyde resin. Brake pads mixtures are very sensitive to moisture, especially ceramic NAO mix (non-asbestos organics) contains the biggest amount of organic components. In the first stage raw resin was analyzed (fresh and hydrated) by IR-oven, IR spectroscopy, flow index test and simultaneous thermic analysis. In the second stage, the simulation of production and brake pads testing was performed. Chemical composition was determined by X-ray fluorescence spectrometer. Then, compressibility of brake pads was measured (under cold and hot) and temperature curves over time were detected. The measurements identify resin as critical and key material. This fact was proven by dependence between its sensibility character to humidity on increasing compressibility. The main aim of master´s thesis was to eliminate of issues during NAO brake pads production, to find root cause, and finally to described the consequences of high compressibility in real process.