Preparation method and application of 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. The preparation method comprises the following steps of: (A) preparing a prefabricated part; (B) performing deposition densification on the prefabricated part by adopting a chemical vapor deposition permeation process to prepare a carbon matrix; (C) preparing an impregnation liquid by taking polycarbosilane as a silicon source, introducing protective gas for high-temperature cracking, and repeating the impregnation and high-temperature cracking operations until an intermediate with a preset density is obtained; and (D) placing silicon particles in a graphite crucible, separating the intermediate from the silicon particles by using a graphite rod, heating the silicon particles to an evaporation state, guiding gaseous silicon to permeate into different side surfaces of the intermediate under a vacuum condition, and carrying out a uniform gas-phase siliconizing reaction to obtain the carbon-ceramic friction material with higher density and uniform composition. The prepared friction material can be applied to brake 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, smooth braking, corrosion resistance, oxidation resistance, high temperature resistance, strong environmental adaptability (such as friction factors do 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-pyrolysis process (PIP), chemical vapor infiltration process (CVI), liquid phase siliconizing reaction sintering process (LSI) and gas phase siliconizing reaction sintering process (GSI). ). [0004] The above preparation methods still have the following problems in the current practi...

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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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