A kind of prestressed fiber reinforced c/sibcn ceramic composite material and preparation method thereof

Abstract

The invention provides a prestressed fiber reinforced C / SiBCN ceramic composite material and a preparation method thereof, belonging to the technical field of ceramic matrix composite materials. The invention improves the interlayers of the fiber preform in the process of repeating the PIP, introduces Z-direction prestressed fibers along the direction perpendicular to the interlayer of the fiber preform, and introduces the Z-direction prestressed fibers into the SiBCN ceramic matrix by grinding and drilling holes. The prestressed fibers perpendicular to the axial direction can offset the internal stress from the inside to the outside of the composite material during the process of PIP impregnation and pyrolysis to prepare thicker samples, improve the mechanical properties of structural ceramics, and avoid excessive fiber pull-out and layering. Moreover, the Z-direction fibers can enhance the mechanical properties of the material along the axial direction, which not only reduces the internal stress of the composite material, but also improves the bonding state of the matrix and the reinforcement fibers, which solves the problem of continuous carbon fiber reinforced SiBCN ceramic matrix. The problem of premature cracking between the layers of the composite matrix.

Description

technical field [0001] The invention relates to the technical field of ceramic matrix composite materials, in particular to a prestressed fiber reinforced C / SiBCN ceramic composite material and a preparation method thereof. Background technique [0002] Carbon fiber reinforced silicon boron carbon nitride matrix composite material (C / SiBCN composite material) is based on carbon fiber or carbon fiber fabric such as carbon cloth, carbon felt, etc. The pyrolysis process is to immerse the fiber preform in the polymer precursor solution, crosslink and solidify the dipped preform under specific conditions, and finally convert it into an inorganic ceramic matrix during the ceramic transformation process of high temperature pyrolysis. , through multiple cycles of impregnation and pyrolysis, a relatively dense ceramic matrix composite material is finally obtained by processing a light-weight and high-strength wave-absorbing composite material. [0003] C / SiBCN ceramic matrix composi...

AI Technical Summary

Problems solved by technology

However, in the process of preparing C / SiBCN ceramic composites by PIP process, the number of impregnation pyrolysis often has a great impact on the volume and internal expansion stress of the preform, which eventually leads to the large composite material There are obvious cracks and cracks on the surface

The traditional solution is often to achieve the role of a diffusion barrier by introducing an interface layer to protect the fiber from chemical damage: for example, the introduction of pyrolytic carbon (PyC) interfacial thermal oxidation improves the fracture behavior, but this will affect the absorbing properties of the material ; or use the metal cladding method, using the characteristics of the metal linear expansion coefficient > ceramics and good toughness and tensile strength to apply prestress to the ceramic matrix composite material, but as the main application object of the wave-absorbing coating at high temperature, the melting point of the metal is low The characteristics cannot meet the requirements of use at high temperature

Images