Ceramic matrix composites, with their excellent properties of being lightweight, high-strength, heat-resistant, and corrosion-resistant, have become strategic materials in aerospace, new energy, and high-end manufacturing fields. The slurry, as a core step in the preparation process, directly determines the microstructure and final properties of the composite material. Ceramic matrix composite slurry is a multi-component synergistic system. By rationally controlling the proportions and dispersion states of each component, the performance of the composite material can be precisely optimized to meet the application requirements of different scenarios.
The composition of ceramic matrix composite slurry has a clear functional division, mainly including three core parts: the ceramic matrix, the reinforcing phase, and the binder and solvent. Each component works in concert and is indispensable. The ceramic matrix, as the main framework of the slurry, plays a crucial role in supporting the reinforcing phase and transferring loads. Commonly used ceramic matrix materials include alumina and silicon carbide. These materials themselves possess extremely high hardness and heat resistance, laying the foundation for the excellent properties of the composite material.
The reinforcing phase is the core component for improving the overall performance of ceramic matrix composites. Its role is to compensate for the shortcomings of a single ceramic matrix, such as high brittleness and insufficient toughness. Common types include fibers, whiskers, and nanoparticles. Fibers and whiskers effectively inhibit the propagation of internal cracks, improving the toughness and fracture resistance of the composite material. Nanoparticles, such as carbon nanotubes and graphene, with their extremely high specific surface area and excellent mechanical properties, can further enhance the strength and functionality of the composite material. Binders and solvents play a role in dispersing and binding the components, ensuring good flowability and formability of the slurry, facilitating subsequent preparation processes, and ensuring the integrity of the molded green body.
In the slurry preparation process, the uniform dispersion of the reinforcing phase is a key challenge, especially for nanoscale and fiber-based reinforcing phases, which are prone to agglomeration and entanglement due to intermolecular forces, preventing them from fully exerting their reinforcing effect and even affecting the performance stability of the composite material. The application of ultrasonic technology effectively solves this problem and has become a core method in the slurry dispersion process.
Ultrasonic action utilizes the mechanical and cavitation effects generated by high-frequency vibration to efficiently disperse the slurry system. On the one hand, high-frequency vibration can break the agglomeration forces between nano-reinforcing phases (such as carbon nanotubes and graphene), dispersing them into individual nano-units and ensuring uniform distribution of the nano-reinforcing phases within the ceramic matrix. On the other hand, ultrasonic vibration can effectively prevent entanglement of fibrous reinforcing phases, allowing the fibers to spread uniformly and fully exert their crack resistance and toughening effects.
The performance of the ceramic matrix composite material after ultrasonic dispersion treatment is significantly improved, with not only greatly enhanced wear resistance and toughness but also optimized functionality. Practice shows that wear-resistant ceramic matrix composite materials prepared using ultrasonic dispersion technology can achieve a strength increase of over 30%, greatly expanding the application range of ceramic matrix composites. With the continuous development of material preparation technology, the optimization of ceramic matrix composite material composition and the upgrading of ultrasonic dispersion processes will drive the development of ceramic matrix composites towards higher performance and wider applications.
