Preparation method and application of a carbon ceramic friction material

Abstract

The invention relates to the technical field of carbon-ceramic composite materials, and discloses a preparation method and application of a carbon-ceramic friction material, comprising the following steps: A) making a prefabricated part; C) using polycarbosilane as the silicon source to make an impregnating solution, introducing a protective gas for pyrolysis, and repeating the impregnation-pyrolysis operation until an intermediate with a predetermined density is obtained; D) placing it in a graphite crucible For silicon particles, graphite rods are used to separate the intermediate from the silicon particles, and the silicon particles are heated to an evaporating state. Under vacuum conditions, gaseous silicon is guided to infiltrate into different sides of the intermediate, and a uniform gas-phase siliconization reaction is performed to obtain a dense density. Higher, uniform composition carbon ceramic friction material. The prepared friction material can be applied to braking parts of automobiles or rail transit systems.

Description

technical field [0001] The invention relates to the technical field of carbon-ceramic composite materials, in particular to a preparation method and application of a carbon-ceramic friction material. Background technique [0002] Carbon-ceramic composite materials have the advantages of low density, wear resistance, high friction coefficient, stable braking, corrosion resistance, oxidation resistance, high temperature resistance, strong environmental adaptability (such as friction factor does not decline in wet state) and long life. An ideal new high-performance friction material. [0003] At present, there are four main processes for preparing carbon-ceramic composites: precursor impregnation and pyrolysis (PIP), chemical vapor infiltration (CVI), liquid phase siliconizing reactive sintering (LSI) and gas phase siliconizing reactive sintering (GSI). ). [0004] The above preparation method still has the following problems in the current practical application: (1) The poro...

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Problems solved by technology

[0004] The above preparation methods still have the following problems in the current practical application: (1) The porosity of the composite material prepared by the precursor impregnation-cracking process is relatively high, because the volume shrinkage is large during the conversion of the organic precursor, and the internal stress generated by the shrinkage is not conducive to improving the material. (2) The gas utilization rate of the chemical vapor infiltration process is low, the densification speed is slow, the deposition cycle is long, and the manufacturing cost is high; the composite material prepared by it has 10% to 15 % residual porosity, it is difficult to make components with larger wall thickness; (3) liquid phase siliconizing reaction sintering process, in which, during the reaction process between molten Si and matrix C, it will inevitably react with C fiber, and C fiber The properties are degraded by Si Si, and at the same time, a certain amount of Si remains in the composite material, which will cause the composite material to become brittle and reduce the creep resistance; (4) The gas phase silicon infiltration reaction sintering process is similar to the liquid phase silicon impregnation process, Only using vapor phase silicon instead of liquid phase silicon as the infiltrating substance and reactant can effectively increase the penetration rate and penetration depth, but the existing silicon vapor evaporates from bottom to top, resulting in uneven silicon infiltration at different positions of the composite material , it is easy to cause uneven components of carbon-ceramic composite materials, and the problem of easy cracking during use

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