一、 Core Features and Advantages
1. Extremely high heat resistance
High softening point: up to about 1730 ℃, much higher than ordinary glass.
Usage temperature: The long-term usage temperature can reach 1100 ℃, and the short-term usage temperature may even be higher.
Excellent thermal shock stability: The coefficient of thermal expansion is extremely low (about 5.5 × 10 ⁻⁷/℃), and it can withstand severe temperature changes without breaking (for example, immediately putting a red hot quartz glass sheet into cold water will not explode).
2. Excellent optical performance
Wide range of light transmission: not only visible light, but also efficient transmission of ultraviolet (UV) and infrared (IR) rays. This is an irreplaceable reason in applications such as UV sterilization equipment and infrared heating furnaces.
High transmittance: In the visible light range, the transmittance can reach over 93%, providing a clear and distortion free field of view.
3. Good chemical stability
It has extremely strong acid resistance and hardly reacts with other inorganic acids except hydrofluoric acid (HF) and hot phosphoric acid (H3PO ₄).
It can also resist the erosion of many acidic substances at high temperatures.
4. High electrical insulation strength and arc resistance
High resistivity makes it an excellent high-temperature insulation material.
5. Mechanical performance
High hardness and scratch resistance. But its brittleness is similar to that of ordinary glass, and it is more sensitive to sharp impacts and point loads.
二、 As an advantageous scenario for mirror applications
Based on the above characteristics, quartz glass lenses are commonly used in the following extreme or special working conditions:
High temperature environment: boiler observation window, high-temperature furnace, heat treatment equipment, glass melting furnace.
Environment requiring heat shock resistance: chemical reactors with drastic fluctuations in reaction temperature, rapid cooling/heating equipment.
Environments that require UV radiation to pass through: UV sterilization equipment, water treatment systems, photochemical reactors.
Scenes that require observation of high-temperature internal processes, such as observation windows in combustion chambers and sintering furnaces.
Environment with high purity requirements: Quartz glass itself has extremely high purity and will not contaminate the medium, making it suitable for the production of polycrystalline silicon, semiconductors, and high-purity chemicals.
三、 Disadvantages and Precautions for Use
Despite its excellent performance, quartz glass sheets also have their weaknesses, which must be noted during use:
1. Poor alkali resistance
At high temperatures, alkaline solutions such as NaOH and KOH can cause severe corrosion to quartz glass. Careful selection or protective measures should be taken under such working conditions.
2. Mechanical impact performance
Like all glass, it is essentially a brittle material that is not resistant to mechanical impact and knocking. Soft gaskets (such as graphite, polytetrafluoroethylene (PTFE)) must be used during installation, and bolts must be tightened uniformly according to torque requirements to avoid local stress.
3. High cost
The cost of raw materials and production processes (high-temperature melting) is much higher than that of ordinary mirror glass, and the price is expensive.
4. High processing difficulty
Quartz glass has high hardness and brittleness, and secondary processing such as cutting, grinding, and drilling is difficult, requiring specialized equipment and processes.
