Introduction of Silicon Nitride Products

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Silicon nitride powder features high purity, small particle size distribution, and high specific surface area and so on. Its hardness is 9 to 9.5, knoop hardness about 2200, micro-hardness 32630Mpa; the melting point is 1900 degrees Celsius, insoluble in water, soluble in hydrofluoric acid; the elastic modulus of nanometer silicon nitride is 28420-46060Mpa, flexural strength 147Mpa, the compressive strength 490Mpa (reaction sintering), which is an important structural ceramic material and super hard material with lubricity, wear resistance, high resistance to corrosion and oxidation in high temperature. It is also resistant to thermal shock and will not break after being heated in air to 1000°C, rapidly cooled and then heated again. Silicon carbide porcelain components can be produced in a low temperature, with good dimensional stability and high mechanical strength.

Technical Index

Silicon nitride powder is white, more than 99% purity, with an average particle size of 25nm, crystalline amorphous, and its specific surface area is 50m2/g.

Chief Applications

a. Manufacturing precision structural ceramic components: such us metallurgy, chemical, machinery, aviation, aerospace and energy industries which used as ball and roller for rolling bearing, sliding bearings, sleeve, valves, device required high temperature resistance and corrosion resistance;

b. Surface treatment of metals and other materials; such as molds, cutting tools, automotive turbine rotor blades and cylinder wall coatings;

c. Preparation of high performance composite materials: such as metals, ceramics and graphite matrix composites, rubber, plastics, coatings, adhesives and other polymer-based composite materials;

d. The application of nano silicon nitride in high wear-resisting rubber: Nanoscale silicon nitride NSN series ultra wear-resisting rubber reinforcer has gained remarkable application effects. Tests showed , the endurance can withstand more than 100 million times of wearing by adding 1-3 portions of NSN powder in the main rubber ternary propylene rubber bellows, without adding NSN ‘s powder, the corrugated pipe had cracked after just 20 million times;

e. Metal surface wear-resistant composite coating applications. Nitride has high hardness, low coefficient of sliding friction. Their mechanical property is high compared to other ceramic materials, but still lagging behind the metallic material. Nevertheless, its hardness variation with temperature is much less than the metal material. Temperature strength of silicon nitride can be kept above 800 degrees Celsius; will even remain comparable strength in 1200°C~1400°C. It’s applied in molds, cutting tools, turbine blades, turbine rotor and cylinder wall coating;

f. Nano silicon nitride for human body infrared absorption in specialty textile: nano silicon powder is nylon and polyester can enhance conductivity. The rate of nano silicon nitride’s body infrared absorption is at 97% or more, which is the best infrared absorption superfine textile additives;

g. In LED light-emitting materials: nano silicon nitride fluorescent powder is a kind of light-emitting material with one or two phosphor luminescence centers. The energy transition process belongs to f-d transition; when given appropriate energy externally, electrons of the ground state levels are excited to high energy levels to release energy in the form of light-emitting. Since the 5d orbital is at the highest level, not like the 4f orbital which is obscured by the electron cloud of the external orbital, its transition process is highly influenced by the external environment that it presents a wide spectrum of morphological spectrum. Then the study and test showed, the smaller the particle size of the silicon nitride raw material, the broader the produced excitation frequency band is.