Quartz sheet overview
Quartz sheets, usually smelted and cut by quartz, have a silica content of over 99.99%. The hardness is seven grades, and it has the characteristics of high temperature resistance, low thermal expansion coefficient, thermal shock resistance and good electrical insulation performance. It is usually colorless and transparent, and its visible light transmittance is 85% or more.
First, optical performance
The optical properties of quartz plates are unique. They can pass through far ultraviolet rays, are the best for all UV-transparent materials, and can transmit near-infrared spectra through visible light. Because quartz glass is resistant to high temperature, its thermal expansion coefficient is very small, its chemical stability is good, and its bubbles, stripes, uniformity and birefringence are comparable to those of ordinary optical glass, so it works with high stability optical coefficients in various harsh occasions. Essential optical material. According to its optical properties, it can be divided into three categories: 1. Far-UV optical quartz glass JGS1 is transparent in the ultraviolet and visible spectrum; no absorption band in the range of 185-250nm; strong absorption band in the range of 2600-2800nm; Non-luminous, stable optical radiation. 2. Ultraviolet optical quartz glass JGS2 is transparent in the ultraviolet and visible spectrum; no absorption band in the range of 200-250nm; strong absorption band in the range of 2600-2800nm; non-luminous, stable optical radiation. 3. Infrared optical quartz glass JGS3 is transparent in the visible and infrared spectral range; there is no obvious absorption band in the range of 2600-2800 nm. Compared to ordinary silicate glass, transparent quartz glass has excellent permeability throughout the entire wavelength range. The spectral transmission in the infrared region is larger than that in ordinary glass; in the visible region, the transmittance of quartz glass is also relatively high. In the ultraviolet region, especially in the short-wave ultraviolet region, spectral transmittance is better than other glasses. The multi-spectral transmittance is affected by three factors: reflection, scattering, and absorption. The reflection of quartz glass is generally 8%, the ultraviolet region is larger, and the infrared region is smaller. Therefore, the transmittance of quartz glass is generally not more than 92%. The scattering of quartz glass is relatively small and can generally be ignored. The spectral absorption and the impurity content of quartz glass are closely related to the production process; the transmittance in the band below 200 nm indicates the content of metal impurities; the absorption of 240 sodium indicates the number of oxygen-deficient structures; The absorption of the band is due to the presence of transition metal ions, and the absorption of 2730 sodium is the absorption peak of the hydroxyl group, which can be used to calculate the hydroxyl content. The spectral transmission performance is calculated by spectral absorption of hydroxyl groups: A GE's formula: C=910/T * LOG10(Ta/Tb)mm-1 C: hydroxyl content (C, ppm) T: thickness (mm) Ta : transmittance of 2600 sodium wavelength Tb: transmittance of 2730 nanometer wavelength B: China's national standard calculation formula: C = 96.5 / d * LG10 (Ia / I) mm-1 C: hydroxyl content (ppm) d: thickness (cm) Ia: distance from the baseline of 2730 sodium to the zero line (mm) I: distance from the absorption peak of the sodium nanometer to the zero line (mm) spectral transmittance: thickness 1mm) other thickness spectral transmittance can Derived by the formula: T = (1-R)2 e -at T: Transmittance R: single reflection loss. e: natural logarithmic base. t: thickness (cm) spectral transmittance wavelength nm
Second, physical properties
Quartz sheet is a special industrial technology glass made of silica, which is a very good basic material. Quartz sheet has a series of excellent physical and chemical properties, such as: 1, high temperature resistance. Quartz glass has a softening point temperature of about 1730 ° C and can be used at 1100 ° C for a long time. The maximum use temperature can reach 1450 ° C in a short time. 2, corrosion resistance. In addition to hydrofluoric acid, quartz glass hardly reacts with other acids. Its acid resistance is 30 times that of ceramics and 150 times that of stainless steel. Especially at high temperatures, it is impossible for any other engineering materials. Comparable. 3. Good thermal stability. The glass has a very small thermal expansion coefficient and can withstand severe temperature changes. The quartz glass is heated to about 1100 ° C and will not burst when placed in normal temperature water. 4, good light transmission performance. Quartz sheet has good light transmission performance in the whole spectrum of ultraviolet to infrared, and the visible light transmittance is above 93%, especially in the ultraviolet spectrum region, the maximum transmittance can reach 80 or more.
Third, the application
The formation of quartz flakes is a result of the high viscosity of the melt. Used in the manufacture of semiconductors, electric light sources, semi-conductive communication devices, lasers, optical instruments, laboratory instruments, electrical equipment, medical equipment and chemical instruments resistant to high temperature and corrosion, chemical, electronics, metallurgy, building materials and national defense industries, applications Very extensive. Quartz sheet has high precision, no bubbles, smooth surface, corrosion resistance and good light transmission. It is especially suitable for optical, electronic, chemical, military and other optical instruments.