Quartz glass, also known as fused quartz or fused silica, is a high-purity material composed primarily of silicon dioxide (SiO₂) with a purity level exceeding 99.9%. It is renowned for its exceptional thermal, optical, and chemical properties, making it an ideal choice for demanding applications.
Critical properties of quartz glass include:
- High-Temperature Resistance: Quartz glass can withstand temperatures up to 1,200°C (2,192°F) continuously and can tolerate short-term exposures up to 1,600°C (2,912°F) without significant structural changes.
- Low Thermal Expansion: It has an extremely low coefficient of thermal expansion, approximately 5.5 x 10⁻⁷/°C, which helps maintain dimensional stability under varying temperatures, making it suitable for precision applications.
- Optical Clarity: Quartz glass exhibits excellent optical transparency in the ultraviolet (UV) and visible spectrum, with transmission rates above 90% in the 200-2,500 nm wavelength range. This makes it ideal for UV and high-intensity light applications.
- High Chemical Purity and Resistance: The high purity of quartz glass ensures minimal contamination in sensitive processes. It is highly resistant to most acids and alkalis, except hydrofluoric acid, and remains inert in harsh chemical environments.
- Electrical Insulation: With a dielectric constant of 3.8 at 20°C and a high dielectric strength, quartz glass serves as an excellent insulator, maintaining stability under high voltages and frequencies.
- Mechanical Strength: Despite its brittleness, quartz glass possesses a tensile strength of about 50 MPa and a compressive strength of around 1,100 MPa, making it capable of withstanding mechanical stresses in various industrial applications.
- Low Thermal Conductivity: Its thermal conductivity is approximately 1.4 W/m·K at room temperature, providing adequate thermal insulation and minimizing heat transfer.
Quartz glass is widely used in industries such as semiconductor manufacturing, optics, telecommunications, and scientific research due to these quantifiable properties. Its unique combination of high purity, thermal stability, and optical clarity makes it indispensable for high-performance and precision applications.
