Quartz glass is a glassy substance composed of a single component of SiO2, containing trace metal impurities and more or less hydroxyl (OH), which is a special glass. It is usually called quartz or fused silica in foreign countries. The building materials industry standard (JC/T 185-2013) divides it into three categories: ultraviolet quartz glass (ZS), visible quartz glass (KS) and infrared quartz glass (HS) according to the transmission characteristics.

Because quartz glass has a silicon-oxygen tetrahedral "SiO4" structure on a microscopic level, it has incomparable physical and chemical properties than other glasses. It is called the "King of Glass", so it is widely used in nuclear technology, aerospace, precision optics and semiconductors. industry.

The special structure and production method of quartz glass lead to its excellent performance in several aspects such as purity, expansion coefficient, chemical physics and optics.

1. Purity

Purity is an important indicator of quartz glass, which has a great influence on the physical and chemical properties and scope of use, such as devitrification, high temperature strength, softening point, light transmission, thermal stability, chemical stability, radiation resistance, fluorescence characteristics, etc. Quartz glass used in the semiconductor industry has strict requirements on purity, and a small amount of impurities will have a serious impact on the electrical properties, life and integration of semiconductor materials. The purity of UV synthetic quartz can reach more than 99.9999% (the total content of metal impurities is less than 1ppm).

2. Chemical stability

Quartz glass is an acidic material. Except for hydrofluoric acid and hot phosphoric acid, it is inert to any other acid and is a very good acid-resistant material. At room temperature, alkali and salt will corrode quartz glass slightly, so quartz glass can also be used when contacting these reagents.

3. Thermal stability

Quartz glass has a very low thermal expansion coefficient, about 5.5×10-7/℃, which is one twentieth that of ordinary glass. It also has good thermal shock resistance. At the same time, quartz glass also has high temperature resistance. , It can be used for a long time at 1200℃. Ultra-low expansion or even zero-expansion quartz glass has become a current research and development hotspot.

4. Optical performance

Quartz glass has unique optical properties, from deep ultraviolet to near-infrared spectra (185-3500nm) with high transmittance.

In short, quartz glass has excellent properties such as high temperature resistance, low thermal expansion coefficient, good chemical stability, excellent electrical insulation, low and stable ultrasonic delay performance, and full spectrum transmission. It also has excellent properties such as bubbles, stripes, uniformity, and stress birefringence. And mechanical properties are irreplaceable for other optical glass. Quartz glass is one of the indispensable new materials in the fields of cutting-edge technology (space technology, nuclear technology, national defense equipment), as well as in the semiconductor, optical communications, and electric light source industries.