CN-117923913-B - Multi-element ultrahigh-temperature nano multiphase ceramic matrix composite material and preparation method thereof

Abstract

The invention discloses a multi-element ultra-high temperature nano multiphase ceramic matrix composite and a preparation method thereof, wherein the multi-element ultra-high temperature nano multiphase ceramic matrix composite is formed by compounding multi-element ultra-high temperature nano multiphase ceramic and a porous fiber body, the multi-element ultra-high temperature nano multiphase ceramic consists of oxygen-free silicon-based ceramic and multi-element transition metal carbonitride uniformly distributed in the oxygen-free silicon-based ceramic, and the preparation method comprises the steps of reacting at least two metal element complexes with a silicon-based polymer to obtain a single-source precursor polymer; then placing the porous fiber body into a single-source precursor polymer solution for multiple soaking and cracking to obtain the porous fiber body. The composite material provided by the invention has a nano composite structure, the multi-element single-phase solid solution of the ultra-high temperature ceramic is realized, the types, the contents and the proportion of metal elements are adjustable, the ultra-high temperature ceramic in a matrix is uniformly distributed and has the nano crystal grain size, and meanwhile, the method can avoid the damage to fibers in the preparation process, so that the mechanical property and the oxidation and ablation resistance of the composite material are synchronously improved.

Inventors

• WEN QINGBO
• JIANG TIANXING
• LU LI
• XIONG XIANG
• WANG YALEI
• ZENG YI

Assignees

• 中南大学

Dates

Publication Date

20260508

Application Date

20240122

Claims (5)

1. 1. A preparation method of a multi-element ultra-high temperature nano composite ceramic matrix composite is characterized by comprising the following steps: Step one Fully mixing and reacting a complex of at least two metal elements of Ti, zr, hf, nb, ta, mo and W with a silicon-based polymer in an organic solvent to obtain a single-source precursor polymer impregnating solution, wherein the silicon-based polymer is selected from polysilazane, and a ligand of the complex of transition metal element Ti, zr, hf, ta, nb, mo, W is selected from dimethylamino and diethylamino; Step two Impregnating porous fibrous body Yu Shanyuan precursor polymer for a period of time, then crosslinking and cracking to obtain the multi-element ultrahigh-temperature nano multiphase ceramic matrix composite material, and realizing densification of the composite material by repeating the above impregnation-crosslinking-cracking process for a plurality of times; in the second step, the dipping process is that dipping is carried out under vacuum, normal pressure or pressurized condition for 0.1-48 h, in the second step, the crosslinking temperature is 50-300 ℃, the cracking temperature is 800-1600 ℃ and the cracking time is 0.1-20 h, in the second step, the cycle number of repeated dipping-crosslinking-cracking is 1-18 times; The single-source precursor polymer is prepared by reacting a silicon-based polymer with transition metal micromolecules, and is converted into a multi-element ultrahigh-temperature nano multiphase ceramic consisting of multi-element transition metal carbonitride and anaerobic silicon-based ceramic after high-temperature pyrolysis; The multi-element transition metal carbonitride is of a face-centered cubic crystal structure, two or more metal atoms in the transition metal element Ti, zr, hf, ta, nb, mo, W share a cationic lattice point of the crystal in any atomic number ratio, and C and/or N atoms occupy anionic lattice points to form a single-phase solid solution, and the single-phase solid solution has a chemical formula (Ti a Zr b Hf c Nb d Ta e Mo f W g )C x N 1-x , wherein 0< x <1, a+b+c+d+e+f+g=1, and at least 2 of a, b, C, d, e, f, g are not 0 at the same time).
2. 2. The method of claim 1, wherein in the first step, the reaction temperature is-20-300 ℃ and the reaction time is 10-600 min.
3. 3. The method for preparing a multi-element ultrahigh-temperature nano composite ceramic matrix composite according to claim 1, wherein the mass fraction of the multi-element transition metal carbonitride phase in the multi-element ultrahigh-temperature nano composite ceramic matrix is 0.1% -95%, and the average grain size of at least one phase is less than or equal to 100 nm.
4. 4. The method for preparing the multi-element ultrahigh-temperature nano composite ceramic matrix composite material according to claim 1, wherein the porous fiber body is a carbon fiber preform, a silicon carbide fiber preform or one of porous C/C, C/SiC and SiC/SiC composite material blank, and the open area ratio of the porous fiber body is 5% -80%.
5. 5. The method for preparing the multi-element ultrahigh-temperature nano multiphase ceramic matrix composite according to claim 1, wherein the density of the multi-element ultrahigh-temperature nano multiphase ceramic matrix composite is 1.0-10.0g/cm 3 , and the aperture ratio of the multi-element ultrahigh-temperature nano multiphase ceramic matrix composite is 0.1-45%.

Description

Multi-element ultrahigh-temperature nano multiphase ceramic matrix composite material and preparation method thereof Technical Field The invention belongs to the field of preparation of ceramic matrix composite materials, and in particular relates to a multi-element ultrahigh-temperature nano multiphase ceramic matrix composite material and a preparation method thereof. Background With the advent of the sky generation in the 21 st century, human beings have been increasingly developing in the near space, and in particular, the competition in the field of hypersonic aircrafts and the like has been increasing. When the aircraft flies at hypersonic speed, key parts such as nose cones, wing front edges and the like are required to bear high temperature of more than 2000 ℃ generated by pneumatic heating, and strong thermal shock impact, plasma ablation and the like caused by the high temperature, so that the ceramic matrix composite materials such as C/SiC, siC/SiC and the like cannot meet the requirements. The superhigh temperature ceramics (UHTCs, such as HfC, zrC, hfB 2, zrB 2 and the like) have the outstanding advantages of high melting point (> 3000 ℃), high modulus, high hardness, high thermal stability and the like, and are expected to fill the application gap because carbon fiber preforms are introduced into the superhigh temperature ceramics to prepare C/UHTCs superhigh temperature ceramic matrix composite materials in recent years. However, the oxidation and ablation resistance of the ultra-high temperature ceramic (UHTCs) is still to be improved, particularly the oxidation resistance is poor under the condition of medium and low temperature (800-1800 ℃), and the application range and the reliability of the material are severely restricted. In order to improve the oxidation and ablation resistance of the ultra-high temperature ceramic matrix composite, the most common strategy is to conduct multiple phases and diversification. The multi-phase ceramic is prepared by adding a second phase (such as SiC, moSi 2, laB 6, etc.) capable of forming a compact oxide layer into the ultra-high temperature ceramic, and the multi-phase ceramic is prepared by adding one or more transition metal components into the binary ultra-high temperature ceramic to prepare a single-phase multi-element ultra-high temperature ceramic solid solution (such as Ta0.8Hf0.2C,(Zr0.2Ti0.2Hf0.2Nb0.2Ta)C,(Zr0.25Ti0.25Hf0.25Ta0.25)C, etc.). In recent years, in order to further improve the oxidation and ablation resistance of the ultra-high temperature ceramic matrix composite, researchers begin to try to simultaneously carry out diversification and multiple phases, so that the C/(Zr 0.2Ti0.2Hf0.2Nb0.2 Ta) C-SiC and other multi-element multiple phase ultra-high temperature ceramic matrix composite is successfully prepared, and the oxidation and ablation resistance is improved. However, the multi-element ultra-high temperature nano composite ceramic matrix composite with better performance advantage and application potential has not been reported yet. Currently, methods for preparing the ultra-high temperature ceramic matrix composite mainly include a Chemical Vapor Infiltration (CVI), a Polymer Impregnation Pyrolysis (PIP), a Reactive Melt Infiltration (RMI), a Slurry Impregnation (SI), a combination of the above methods, and the like. However, the preparation of the multi-element composite material based on ultra-high temperature ceramic by adopting the method has certain defects that (1) the design and regulation capability of processes such as SI, CVI and RMI on the multi-element composite material matrix is limited, the variety and atomic number ratio of metal elements in the multi-element composite material is difficult to accurately regulate and control, (2) the actual proportion of the ultra-high temperature ceramic phase and the additive phase in the ceramic matrix cannot be flexibly regulated and controlled by the processes such as SI, CVI and RMI, and the like, the potential for further design and development of the composite material is limited (for example, the content of the multi-element composite material in the matrix is controlled according to actual needs, the gradient ceramic composite material with gradually changed content of the ultra-high temperature ceramic is prepared, and the like), (3) the processes such as SI, CVI and RMI cannot prepare the ultra-high temperature ceramic composite material with a nano composite structure, even though uniform distribution of the ultra-high temperature ceramic particles is difficult to realize due to the problem of particle agglomeration, and the reliability of the ultra-high temperature ceramic phase cannot be ensured in extreme environments, and (4) the RMI method is proved to be a very efficient composite material based on the basis, but the ultra-high temperature composite material is easy to react with a high-temperature melt due to the fact that the ultra-high temperature compo