non-ferrous metallurgy–FD2N type Silicon Nitride
Characteristics: thermo stable, Corrosion Resisting, chemical stability and good wear-resistance. The expansion coefficient is small, thermo conductivity good, good strength and toughness and good performance of oxidation under high temperature. The color is white, poison less, high content of αand narrow distribution of particle size.
To produce silicon nitride ceramics like protection tube for thermocouple working under high temperature, lift tube etc.
Mainly application industry: non-ferrous metallurgy and steel industry.
FD2N type Silicon Nitride(si3n4) is mainly used to produce protection tube for thermocouple working under high temperature and lift tube. Due to its good resistance to erosion of molten aluminum and good thermo conductivity, silicon nitride plays an important role in aluminum production. In operations of casting-and-rolling of aluminum and aluminum melting, it could be used to produce casings tubes for temperature-test thermocouple. In addition, the liner for aluminum-melting stove, containers of the melted aluminum and moulds for shaping the final products are all made of silicon nitride. As replacement of the traditional carbon materials for application of electrolyzes, there has been obvious benefit to combine silicon nitride with silicon carbon. This kind of combination has been increasingly applied in Europe, America and Japan.
In China, people have started to use thermocouples casing by silicon nitride tube to test temperature of melted aluminum. This kind of casing tube is much better than tubs made of stain less steel and corundum ceramics. Steel is easy to be corroded by melting aluminum which lead a broken after twenty hours continuous application. Corundum ceramics could not bear high temperature.
In comparison with these materials, silicon nitride could be stable in melted aluminum and would not cracking even it is used to test temperature for over 1200 times. Thermocouple casing made of silicon nitrite could also be used to test temperature of melted zinc and the effect is quite good.