Synthesis of cubic silicon nitride - Harvard University
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Synthesis of cubic silicon nitride
The nitridation of silicon powder was developed in the 1950s, following the "rediscovery" of silicon nitride and was the first large-scale method for powder production. However, use of low-purity raw silicon caused contamination of silicon nitride by and . The diimide decomposition results in amorphous silicon nitride, which needs further annealing under nitrogen at 1400–1500 °C to convert it to crystalline powder; this is now the second-most important route for commercial production. The carbothermal reduction was the earliest used method for silicon nitride production and is now considered as the most-cost-effective industrial route to high-purity silicon nitride powder.
Synthesis and characterization of cubic silicon carbide …
The of silicon nitride and silicon are different. Therefore or can occur, depending on the deposition process. Especially when using PECVD technology this tension can be reduced by adjusting deposition parameters.
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Francisco Zaera Surface Group: Publications
One of the major applications of sintered silicon nitride is in automobile industry as a material for engine parts. Those include, in , for faster start-up; precombustion chambers (swirl chambers) for lower emissions, faster start-up and lower noise; for reduced engine lag and emissions. In , silicon nitride is used for pads for lower , turbocharger for lower inertia and less engine lag, and in for increased acceleration. As examples of production levels, there is an estimated more than 300,000 sintered silicon nitride turbochargers made annually.
examples include boron nitride and silicon nitride
Silicon nitride ball bearings are harder than metal which reduces contact with the bearing track. This results in 80% less friction, 3 to 10 times longer lifetime, 80% higher speed, 60% less weight, the ability to operate with lubrication starvation, higher corrosion resistance and higher operation temperature, as compared to traditional metal bearings. Silicon nitride balls weigh 79% less than tungsten carbide balls. Silicon nitride ball bearings can be found in high end automotive bearings, industrial bearings, , motorsports, high-end MTBs, racebikes, rollerblades and . Silicon carbide bearings are especially useful in applications where corrosion, electric or magnetic fields prohibit the use of metals. For example, in tidal flow meters, where seawater attack is a problem, or in electric field seekers.