Reaction bonded silicon carbide is an extremely strong ceramic with excellent wear and corrosion resistance. It can be formed into various shapes and uses for various applications.
RBSC exhibits about 50% greater strength and hardness than most nitride bonded silicon carbides, and it has also been found to be resistant to chemical and oxidation degradation.
The Process
Reaction Bonded Silicon Carbide is produced from preformed bodies composed of SiC particles, carbon and a binder. When molten silicon infiltrates this preform, some carbon is consumed and more SiC carbide crystallizes within its pores.
This reaction produces a two-phase material with low porosity and great strength up to 1350C, which is used for gas turbine components, rotor blades, and bearings.
Preforms must be carefully selected to guarantee full conversion of carbon into SiC. Carbon in a preform can affect properties such as strength, density and elastic modulus negatively.
Reaction bonded silicon carbide is shrinkage free and widely used in components that need high thermal conductivity. This characteristic makes it ideal for applications such as high-voltage power supplies, electric vehicles, inverters for green energy production, industrial motor drives and wireless base stations.
Properties
Silicon carbide is an alumina ceramic material with numerous advantageous qualities. It’s lightweight, strong and has excellent abrasion resistance. Furthermore, its thermal conductivity and low thermal expansion make it suitable for wear applications like pipe liners or flow control chokes.
Reaction Bonded Silicon Carbide (RBSC) is a type of silicon carbide created through the reactive infiltration of molten Si into preforms composed of SiC particles and carbon. RBSC has many uses due to its lightweight nature, excellent mechanical properties, and corrosion-resistance.
Reaction-bonded silicon carbide (RBSC) is ideal for high temperature applications due to its capability of being sintered up to 1530 degC without needing heat treatment processes. Furthermore, alloys like aluminum and titanium can be added to RBSC Reaction Bonded Silicon Carbide in order to increase thermal conductivity while still retaining most of their desirable mechanical characteristics.
Applications
Reaction-bonded silicon carbide (RB-SiC) has many applications in high power devices such as electric vehicles, inverters for green energy, industrial motor drives and smart grids. Due to its thermal conductivity and excellent mechanical properties, RB-SiC has found widespread usage.
Furthermore, RB-SiC exhibits a low coefficient of thermal expansion (CTE) and can accommodate aluminum and titanium alloys for improved thermal conductivity. As such, this makes RB-SiC an ideal material for heat dissipation in advanced power modules with high speed and density components.
Reaction bonded silicon carbide is ideal as a sealing material for piston caps and valve stem tips on engines that require high wear resistance. Metal-ceramic seals based on brazing or direct bonding techniques have long been employed in this area; however, they have several drawbacks.
Manufacturing
Reaction bonded silicon carbide is an impressive ceramic material renowned for its exceptional hardness and resistance to extreme temperatures. This tough ceramic finds application in various industries due to its durability and strength, as well as its outstanding thermal conductivity and low thermal expansion index.
The manufacturing process for reaction bonded silicon carbide involves several steps, such as prepping a silicon supplying body, pressing it against one surface of a preform and heating it in a reaction bonding furnace. It is especially crucial to heat these bodies above their melting point under vacuum or an inert atmosphere so that any fused silicon from the supplying body can seep into the preform.
Reaction bonded silicon carbide can be produced in a variety of shapes, such as cone and sleeve shapes and engine components. It has high wear- and corrosion resistance which makes it popular in automotive applications. Furthermore, its thermal shock resistance and strength make it popular across metallurgy and refractory industries.