A method for pressureless connection between c/c composite materials

Abstract

The invention relates to a pressure-free connection method of C / C composite materials. The method is characterized by taking the C / C composite materials with porous surface layers and complete internal structures as connection mother materials, converting a ceramic connection layer into a liquid phase under high temperature, diffusing and infiltrating the liquid phase into a connection substrate, and reacting the liquid phase with the connection substrate to generate chemical combination, and achieving successful connection of the C / C composite materials under the pressure-free condition, wherein the connection strength of a connector is 4.71-6.87MPa. The pressure-free connection method of the C / C composite materials has the beneficial effects that the C / C composite materials with the porous surface layers and complete interiors are used as the connection mother materials, a ceramic intermediate layer is converted into the liquid phase under high temperature, the liquid phase is diffused and infiltrated into the connection substrate to react with the connection substrate and generate chemical combination, the successful connection of the C / C composite materials under the pressure-free condition is achieved, and the connection strength of the connector is 4.71-6.87MPa. Through the method, the problem that the conventional hot pressing connection method is incapable of connecting specially-shaped parts or curved surfaces of the C / C composite materials can be solved.

Description

technical field [0001] The invention belongs to a method for connecting C / C composite materials, and relates to a method for connecting C / C composite materials without pressure, in particular to a method for connecting C / C composite materials using high-temperature instantaneous liquid phase under pressure-free conditions process method. Background technique [0002] C / C composite materials have the advantages of low density, excellent high-temperature mechanical properties, thermal shock resistance and high-temperature ablation resistance, and are considered to be irreplaceable thermal structural materials in the aerospace field. However, due to the difficulty of one-time weaving and forming of preforms and the high requirements for deposition equipment, it is difficult to achieve one-time molding of large and complex C / C composite components. Therefore, it is very important to use connection technology to realize the combination of C / C composite materials. . At present, ...

AI Technical Summary

Problems solved by technology

If a mechanical connection is used, it is necessary to drill holes in the C / C composite material, which will damage the macroscopic continuity of the material. At the same time, the introduction of bolts will lead to local stress concentration and affect the performance of the connection.

The bonding method usually uses organic matter as the connecting layer, and the pyrolysis of the organic interlayer greatly limits the application of the connecting member under high temperature conditions.

Diffusion bonding is a process of manufacturing integral joints through diffusion bonding at the atomic level. Due to the use of physical diffusion and chemical reactions, the resulting joint interfaces are well bonded. However, at present, most diffusion bonding is carried out under hot-pressing conditions, and it is impossible to achieve C / C Connection of special-shaped parts or curved surfaces of composite materials

[0003] Document 1 "Jie Wang, KeZhi Li, et al., The study on joining carbon / carboncomposites using Ti–Ni–Si compound[J].Materials Science and Engineering A, 2012,547:12–18" proposes a thermal The method of connecting C / C composite materials by pressing connection technology, although the bonding strength of the joint obtained by this method is high, but the hot pressing process limits the geometry of the connecting parts, it is difficult to extend to special-shaped parts or curved surface connection

Images