High-Purity Fused Silica Powder

High-purity fused silica powder is an amorphous, non-crystalline form of silicon dioxide produced by melting high-quality quartz sand at extremely high temperatures followed by rapid cooling and pulverization. This material exhibits exceptional thermal stability, chemical inertness, and low thermal expansion coefficient, making it indispensable in advanced manufacturing processes. It serves as a critical raw material in the production of precision ceramics, investment casting molds, refractory linings, and electronic components. The material's high purity and consistent particle size distribution ensure reliable performance in demanding industrial environments where contamination or dimensional instability cannot be tolerated. The powder is characterized by a minimum silicon dioxide content of 99.9%, a median particle diameter (D50) ranging from 5 to 50 micrometers, and a bulk density between 0.5 and 0.8 g/cm³. Its thermal expansion coefficient is exceptionally low, between 0.5 and 0.6 ×10⁻⁷/°C from 0 to 300°C, and it exhibits a loss on ignition of no more than 0.1% at 1000°C. The specific surface area, measured by BET, falls between 1 and 10 m²/g. With a Mohs hardness of 7, it offers good abrasion resistance. Its dielectric constant is stable at 3.8–4.0, and volume resistivity is at least 10¹⁶ Ω·cm, making it suitable for electronic substrates. The maximum continuous operating temperature is 1100°C. Moisture content is kept below 0.05% to prevent agglomeration, and the pH value in water is neutral (6.0–7.5). These parameters are provided as reference ranges; actual values should be confirmed for the specific grade or application. The product is listed in a neutral directory and is not manufactured or sold by the directory. Always verify model-specific specifications and applicable standards with the legal manufacturer or supplier.

The working principle of high-purity fused silica powder relies on its amorphous structure and high purity. The non-crystalline arrangement of silicon dioxide molecules provides dimensional stability under thermal cycling, as the low thermal expansion coefficient minimizes volume changes. Chemical inertness arises from the strong Si-O bonds and the absence of impurities that could react with environments. The powder's consistent particle size distribution ensures uniform packing and predictable behavior in ceramic bodies, casting molds, and refractory linings. Its high electrical resistivity and stable dielectric constant make it an effective insulator in electronic applications. The material's performance is governed by its purity, particle morphology, and surface characteristics, which are controlled during manufacturing. In use, the powder must be handled to avoid contamination, and its properties should be verified against the specified parameters for the intended application.