The Study Of Hybird Fibers Reinforced Resin-based Friction Materials

In recent years, increasing vehicle speed leads performance requirement of frictionmaterials, used as brake materials, will also need to be improved. Since a variety of advancedmaterials had been applied in the study of friction material, and many new friction materialshave come into being.Fiber-reinforced resin-based friction material is one class of friction materials, which hasa wide application prospect. In general, this type of friction material played certain advantagesof reinforcing fiber component, so that the friction material has better properties. Compositefibers mixed by two or more fibers have better effect of enhancement on the friction materialthan single-fiber reinforced.However, at this stage, the study of composite fibers is confined in the complex of steelfiber and non-metallic fiber. As a result, this article innovatively studied the mechanism offriction material reinforced by composite fibers, mixed by carbon fiber and ceramic fiber.This article selected phenolic resin modified by nitrile rubber, kaolin, alumina powder,barium as binder, single fiber or hybrid fibers as reinforced body, powders of aluminum,silicon, nickel, reduced iron, copper as supplemented friction performance regulators, todesign and synthesize three kinds of friction materials, which are resin-based friction material,aluminum ceramics reinforced resin-based friction material and carbon fiber/aluminumsilicate ceramic fiber reinforced resin-based friction material. Then the effect of resin content,silicate ceramic fiber content and fiber content of hybrid fibers on performance such ashardness, friction coefficient and its stability and wear rate were studied.Experimental studies have shown that, when dosage of nitrile rubber-modified phenolicresin was18%, the resin-based friction materials had good thermal recession, stable frictioncoefficient and smaller wear rate.Added silicate ceramic fiber improved the wear resistance of ceramic fiber reinforcedresin-based friction material at low temperature, but with rising temperature, wear resistance decreased and wear rate increased. Aluminum silicate ceramic fiber was brittle, so at the sametemperature, the higher the fiber content, the greater the friction coefficient and wear rate.When the ceramic fiber content was more than9%, the hardness of the friction material is toolarge to meet the practical specification of friction materials. The results showed that when thecontent of aluminum silicate ceramic fiber was6to9percent, enhancement of aluminumsilicate ceramic fiber reinforced resin-based friction material reached to the best condition.The performance of carbon fiber, such as wear resistance, high toughness, high thermalconductivity and so on, could make up for the shortcomings of ceramic fibers and furtherimproved the performance of the friction material. The study showed that, when in mixedfibers, carbon fiber content was2to4percent, and ceramic fiber content was4to6percent,friction material had low wear rate, appropriate hardness, stable friction coefficient and goodthermal recession.The observations of friction material worn surface picked that the wear surface offiber-free resin-based friction material was smooth, with flaky scales tilt existing. Brittleceramic fiber caused roughness surface, obvious surface flake, and higher crack occurrenceprobability.Addition of carbon fiber promotes produce of slip film, so that the friction surfacebecomes smooth. Therefore, composite fibers can effectively reduce the surface roughness ofthe friction, and prevent the occurrence of cracks and peeling.