Modified SiCf/SiC composite material and preparation method thereof

Abstract

The invention discloses a modified SiCf / SiC composite material and a preparation method thereof. The preparation method comprises the following steps: 1) by taking carbon black and silicon carbide powder as solid phases, mixing with a liquid phase, adding additives, performing ball-milling mixing and vacuum ultrasonic degassing so as to obtain dipping slurry; 2) putting a silicon carbide fiber into the dipping slurry, performing vacuum dipping, performing overlapping pressing, and drying so as to obtain a carbon-containing preform, wherein the silicon carbide fiber has a boron nitride interface phase; 3) performing calculation simulation on a binary phase diagram of silicon and metals, and performing high-temperature smelting and powder making so as to obtain low-melting point alloy powder; and 4) wrapping the carbon-containing preform with the low-melting point alloy powder, and performing reaction infiltration, thereby obtaining the modified SiCf / SiC composite material. By adopting the preparation method, the sintering temperature of the modified SiCf / SiC composite material is effectively reduced, the melting points of free silicon and alloys in the composite material are increased, the mechanical properties are improved, the service life of the modified SiCf / SiC composite material is further prolonged, the mechanical properties of the modified SiCf / SiC composite material areimproved, the production energy consumption is reduced, and the production cost is lowered.

Description

technical field [0001] The invention relates to the field of preparation of ceramic matrix composite materials, in particular to a modified SiC f / SiC composite material and its preparation method. Background technique [0002] Continuous SiC fiber reinforced SiC ceramic matrix composites (SiC f / SiC composite material) has low density, and has excellent high-temperature mechanical properties, oxidation resistance, thermodynamic stability, corrosion resistance, etc., and has the most application prospects in hot-end parts such as aero-engine turbine blades and combustion chamber liners. In addition, SiC f The / SiC composite material also has low induced radiation, radiation tolerance and excellent microwave absorption performance, and has important application prospects in nuclear fusion reactor cladding materials and structure-function integrated microwave absorption technology. [0003] Traditional preparation of SiC f The preparation methods of / SiC composite material...

AI Technical Summary

Problems solved by technology

[0004] The following shortcomings generally exist in the prior art: 1) The preparation process of the carbon-containing preform is lengthy and complicated; the production of the carbon-containing preform in the prior art includes processes such as weaving, chemical vapor deposition, chemical vapor infiltration, and precursor impregnation and cracking , these processes all have the disadvantages of long time consumption and high energy consumption; 2) The sintering temperature is generally high, causing mechanical damage to SiC fibers, high energy consumption and cost; the melting temperature based on metal silicon is 1416 ° C, which is To achieve liquid silicon infiltration, the liquid silicon infiltration process needs to be carried out at a temperature higher than the melting point

However, high-temperature siliconizing not only damages the mechanical properties of SiC fibers, but also has high energy consumption and high cost; 3) The mechanical properties and oxidation resistance of sintered composite materials are poor; a certain amount of free silicon generally exists in sintered composite materials, and the mechanical strength is low. It is easy to soften at high temperature, and even gasifies and evaporates to form holes, which reduces the mechanical properties and oxidation resistance of composite materials

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