Silicon Carbide Fibers Used In Composite Material Reinforcement

Silicon carbide fibres are a type of high-performance ceramic material whose primary constituents are carbon and silicon. Morphologically, they are divided into whiskers and continuous silicon carbide fibres. They exhibit high-temperature oxidation resistance, high hardness, high strength, high thermal stability, corrosion resistance and low density.

In comparison to carbon fibres, silicon carbide fibres can perform well under extreme conditions. Due to this performance, they have received attention in high-tech sectors such as aerospace, military armaments and equipment. They are frequently used as high-temperature resistant materials and reinforcement components. Additionally, the development of processing technology has extended the applications of silicon carbide fibres. They are now used in advanced sporting goods, automotive exhaust emission dust removal and other civil industrial sectors.

Silicon Carbide Matrix Composites

With the development of science and technology, the performance requirements for high-temperature materials in aerospace, military armaments and equipment have increased. High-temperature materials must exhibit high strength, high modulus, chemical corrosion resistance, creep resistance, oxidation resistance and fatigue resistance in such environments. Silicon carbide fibres provide these properties and show compatibility with ceramic and metal matrices. They are used for composite reinforcement.

* Composite with Ceramic Matrix

A ceramic matrix composite is formed by incorporating reinforcement material into a ceramic matrix. In this composite, the reinforcement serves as the dispersed phase. The ceramic matrix constitutes the continuous phase. Currently, the chemical vapour deposition (CVD) method and the active carbon fibre conversion method are primarily used to produce silicon carbide reinforced ceramic matrix composites.

In aerospace, ceramic matrix composites are primarily used in the hot sections of engine components. These include parts of the aft nozzle, combustion chamber, afterburner, turbine outer ring, guide vane and rotor blade. Such components require the use of high-temperature materials.

* Metal Matrix Composite

Metal matrix composites exhibit properties of both metallic and non-metallic materials. Compared with individual materials, they offer improved mechanical and physical properties such as wear resistance, toughness, controlled thermal expansion and electrical conductivity.

Silicon carbide fibre reinforced metal matrix composites deliver improved performance in terms of specific strength, specific stiffness, thermal expansion coefficient, thermal conductivity and wear resistance. They can be processed into qualified metal matrix composites. In addition, their production costs are lower than those for boron fibres. They are applied in aerospace, military ordnance and equipment, sporting goods and the automotive industry.

Common manufacturing methods for metal matrix composites include powder metallurgy, thermal spraying, casting, high-energy ultrasonic recombination and in-situ recombination methods. Powder metallurgy is the first established approach. Given that the technological principles and processes differ, the properties of composites produced by these methods vary. Each method has certain limitations. For example, the thermal spraying process has a short preparation cycle and high production efficiency. However, it is associated with expensive equipment, high porosity and significant raw material loss.

Typical silicon carbide reinforced metal matrix composites include those with aluminium, titanium, magnesium and copper matrices. Furthermore, many studies have focused on silicon carbide reinforced titanium and aluminium matrix composites.

After decades of research and development, the production processes and properties of silicon carbide fibres have been significantly improved. The precursor production technology is relatively mature. The method of converting active carbon fibres constitutes an important research direction to enable the industrial production of silicon carbide fibres. Moreover, the application of silicon carbide reinforced ceramic and metal matrix composites has gradually extended from aerospace and military sectors to civil industries.