Vývoj metod charakterizace frikčních kompozitů a produktů frikčního procesu

Abstract

Friction composites are significant components of brake lining materials. During braking process friction phenomena causes release of wear particles into the environment. Part of composite of brake lining enters the environment as the non-airborne particles. This fraction settles in the surrounding of roads and can also contaminate soil and surface and ground water. Another part of a friction composite is being released into the environment as the airborne particles. These particles can be transported to a long distance and can adversely affect living organisms, and thus humans. Friction composites used in automotive brake systems are complicated materials composed of a number of components (more than 20) having different properties. To study this material and products of friction process (non-airborne and airborne particles) it is necessary to prepare a friction composite of similar composition as the composites based on phenol-formaldehyde resin commonly used in practice. Methodology of preparation of laboratory samples of friction composites was designed. Reference materials for calibration X-ray fluorescence analysis using this methodology were prepared. Experimental design consisting of chemical analyses of friction composites using XRF methods supplemented by AAS and AES – ICP. Phase composition of the friction composites and its modified forms were analyzed by XRD combined with SEM method and EMAX. To assess the structure of the material and size, morphology and distribution of individual components in the studied samples were also used SEM method and EMAX. Procedure for the analysis of wear particles as a product of friction process using following methods: XRF, XRD and SEM was used. The commercial brake pads JURID is demonstrated usage of designed procedure analysis of the composition and structure of friction composites (based on phenol-formaldehyde resin) and wear particles. The next example shows that the designed methodology for preparation of the friction composites is suitable for assessing the impact of individual components of the friction properties of the resulting composite.