Silicon internal combustion engine

When you pour boiling water into a cold bottle and discover that the bottom drops out with a smart pop, you have re-invented the standard test for thermal shock resistance. Fracture caused by sudden changes in temperature is a problem with ceramics. But while some (like ordinary glass) will only take a temperature "shock" of 80°C before they break, others (like silicon nitride) will stand a sudden change of 500°C, and this is enough to fit them for use in environments as violent as an internal combustion engine. 

Silicon nitride is prized for its hardness (9 out of 10 on the Mohr scale), its wear resistance, and its mechanical strength at elevated temperatures. It melts and dissociates into the elements at 1,900 °C, and has a maximum use temperature near 1,800 °C in the absence of oxygen and near 1,500 °C under oxidizing conditions.41 It also has a relatively low density (3.185 g/cm3). Unlike silicon carbide, silicon nitride is an electrical insulator. The bulk material has a relatively good stability to aggressive chemicals. This combination of properties underlies its uses in internal combustion engines and jet engines. 

Molded silicone rubber articles are generally utilized as seals for equipment running at high temperatures e.g. as crankshaft seals in internal combustion engines or for headlight and gearbox seals. 

The 4-9% Cr alloys are widely used for oxidation resistance in oil-refinery construction. The 12% Cr-Fe alloy is used for steam turbine blades because of excellent oxidation resistance and good physical properties. The 9-30% Cr alloys are used for furnace parts and burners when combined with silicon and nickel, and sometimes other alloying elements, they are used for valves of internal-combustion engines. The approximate upper temperature limits for exposure to air are presented in Table 11.4. 

Owing to its excellent mechanical, thermal, and thermophysical properties, silicon nitride finds applications in aerospace gas turbines, internal combustion engines, heat engines, and a variety of dies, molds and tools for metal manufacturing and forming (Von Hocking et al., 1994 Riley, 1996 Petzow and Herrmann, 2002 Lin et al., 2006). 

Silicon Strengthens ferrite, raises the critical temperatures has a strong graphitizing tendency always present to some extent because it is used, with manganese, as a deoxidizer Silicon steel (0.07% C 4% SI) used for transformer cores used with chromium (3.5%Si 8% Cr) for its high-temperature oxidation resistance in internal combustion engine valves... 

Excellent high temperature properties [1] Strength, creep, fracture toughness, hardness, corrosion/erosion resistance, good thermal schock resistance make silicon nitride ceramics ideal materials for highly stressed structural applications at high temperatures such as internal combustion engines and gas turbines [2,3]. 

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