Silicone rubber is a type of elastomer (rubber-like substance) made up of silicone, which is a polymer made up of silicon, carbon, hydrogen, and oxygen. Silicone rubbers are widely utilized in industry, and they come in a variety of forms. Silicone rubbers are typically one- or two-part polymers with fillers added to improve characteristics or lower costs. Silicone rubber is generally non-reactive, stable, and resistant to harsh conditions and temperatures ranging from 55 to 300 degrees Celsius (70 to 570 degrees Fahrenheit) while still retaining its useful qualities.
The present process of producing silicon carbide for the abrasives, metallurgical, and refractories industries is nearly identical to Acheson's invention. Within a brick electrical resistance-type furnace, a mixture of pure silica sand and carbon in the form of finely crushed coke is built up around a carbon conductor. A chemical reaction occurs when the carbon in the coke and the silicon in the sand mix to generate SiC and carbon monoxide gas while an electric current passes through the conductor. Temperatures range from 2,200° to 2,700° C (4,000° to 4,900° F) in the core to around 1,400° C (2,500° F) at the outside edge during a furnace run, which can last several days.
The energy consumption per run is in excess of 100,000 kilowatt-hours. The finished result consists of a core of loosely interwoven green to black SiC crystals surrounded by partially or fully unconverted raw material at the end of the run. Crushed, ground, and screened lump aggregate is divided into several sizes depending on the final application.
Silicon carbide is made using a variety of innovative techniques for specific uses. Mixing SiC powder with powdered carbon and a plasticizer, shaping the mixture into the appropriate shape, burning off the plasticizer, and then injecting the burnt item with gaseous or molten silicon, which interacts with the carbon to make further SiC, is how reaction-bonded silicon carbide is made. Chemical vapour deposition, a method in which volatile carbon and silicon compounds react at high temperatures in the presence of hydrogen, can produce wear-resistant layers of SiC. Large single crystals of SiC may be formed from vapour for sophisticated electronic applications, and the boule can then be sliced into wafers similar to silicon for construction into solid-state devices. SiC fibres can be generated in a variety of techniques, including chemical vapour deposition and the burning of silicon-containing polymer fibres, for reinforcing metals or other ceramics.
1. O-rings
2. heat-resistant seals
3. caulks, gaskets
4. electrical insulators
5. flexible molds
6. surgical implants
