Silicon carbide, as a high-performance inorganic non-metallic material, possesses characteristics such as high strength, high hardness, high temperature resistance, corrosion resistance, and excellent thermal conductivity. Its slurry form, with its excellent processing adaptability, has been widely penetrated into many high-end manufacturing fields, becoming a key basic material driving industrial upgrading. From efficient heat dissipation of semiconductor chips to wear-resistant protection of industrial equipment, from high-end braking systems to nuclear reactor components in extreme environments, the application scenarios of silicon carbide slurry are constantly expanding, and its performance directly determines the quality and reliability of end products.
In the semiconductor industry, silicon carbide slurry is a core raw material for preparing heat dissipation substrates. With the continuous increase in chip integration, heat dissipation efficiency has become a key bottleneck restricting device performance. Silicon carbide-aluminum nitride composite substrates, with their excellent thermal conductivity, have become an ideal heat dissipation solution for high-end chips, and high-quality silicon carbide slurry is a prerequisite for ensuring the thermal conductivity of the substrate. In the automotive industry, silicon carbide slurry is used in the preparation of brake pads, which can significantly improve the wear resistance and high-temperature resistance of brake pads, extend their service life, and enhance braking safety. Furthermore, in fields such as wear-resistant components in machinery manufacturing and radiation-resistant materials for nuclear reactors, silicon carbide slurry plays an irreplaceable role due to its outstanding stability and durability, providing support for the stable operation of equipment under extreme conditions.
Although silicon carbide slurry has broad application prospects, the dispersion problem during preparation has always been a core bottleneck restricting its performance improvement. Due to the extremely high hydrophobicity of silicon carbide particles, they easily form tight agglomerates in solvents due to intermolecular forces. These agglomerated structures, known as "fish-eyes," are highly stable and difficult to break up effectively using traditional mechanical stirring methods. Simultaneously, the long whisker-like silicon carbide, as a reinforcing phase, is prone to entanglement, which not only reduces the slurry's fluidity but also leads to decreased slurry uniformity, thus affecting the quality of subsequent molding and processing, significantly increasing the difficulty of fabricating complex-shaped parts.
Powder agglomeration further affects sintering density, leading to problems such as porosity defects and inhomogeneous microstructure in the sintered body, ultimately reducing the mechanical properties and reliability of the final product. Traditional dispersion methods are insufficient to fundamentally solve this problem, necessitating a highly efficient and stable dispersion technology to overcome the application bottleneck of silicon carbide slurries.
The emergence of ultrasonic dispersion technology offers a highly efficient solution to the dispersion challenges of silicon carbide slurries, demonstrating significant technological advantages due to its unique cavitation effect. When ultrasound acts on the slurry, it forms numerous microbubbles in the solvent. The impact force generated during the rapid expansion and collapse of these bubbles effectively disrupts the van der Waals forces between silicon carbide particles, completely eliminating "fish-eye" agglomerations and achieving uniform particle dispersion. For long whisker-like silicon carbide, ultrasound can disperse it into single strands or short bundles, precisely controlling the whisker length within the 5-20 μm range. This effectively improves the thixotropy and flowability of the slurry, enabling it to adapt to complex processing techniques such as injection molding and meeting the fabrication requirements of complex-shaped components like turbine rotors.
More importantly, ultrasonic dispersion significantly enhances the overall performance of silicon carbide composites. After ultrasonic dispersion, silicon carbide particles can be uniformly mixed with metal, ceramic, and other matrices, effectively avoiding performance limitations caused by uneven dispersion. Practice has shown that silicon carbide-aluminum nitride composite substrates prepared using ultrasonic dispersion can achieve a thermal conductivity exceeding 150 W/(m·K). Wear-resistant components with uniformly dispersed silicon carbide particles exhibit a wear rate reduction of over 40%, while their mechanical strength and stability are also significantly improved.
With the continuous development of high-end manufacturing industries, the performance requirements for silicon carbide slurries will continue to increase, and the application of ultrasonic dispersion technology will become more widespread. In the future, by continuously optimizing the ultrasonic dispersion process and combining it with technologies such as powder surface modification, it is expected that the dispersion stability and processing performance of silicon carbide slurries can be further improved, promoting its deeper application in semiconductors, new energy, and high-end equipment manufacturing, injecting new impetus into the high-quality development of these industries.
