What Are Glass-Ceramics?
Glass-ceramics are a type of material created by reheating special glass compositions and uniformly precipitating crystals within the glass, known as crystallized glass. These materials have a smooth, shiny surface and can be transparent or milky white. Unlike ordinary amorphous glass, glass ceramics contain fine crystals, making them stronger and more heat-resistant, thus suitable for diverse industrial applications.
Applications of Glass-Ceramics
Glass-ceramics have a broad range of uses:
- In household items like heat-resistant tableware and microwave oven turntables.
- As heating equipment components, such as cooktop glass and oven windows.
- In disaster prevention as fire-resistant glass due to their high-temperature resistance and strength.
- For protective covers in cameras, lighting fixtures, and mobile devices.
- As materials in physics, chemistry, satellite construction, precision bearings, and insulation.
- As substrates in high-power LEDs and LDs, used in automotive, lighting, display, and medical fields.
Principle of Glass-Ceramics
Glass-ceramics are produced by reheating specially composed glass to precipitate microcrystals, enhancing strength and thermal shock resistance. The properties of glass ceramics depend on the crystals’ type, size, quantity, and residual glass phase, which are determined by the glass composition and reheating conditions.
Characteristics of Glass-Ceramics
Key characteristics include resistance to thermal shock and minimal expansion, preventing cracking under rapid temperature changes. This makes them suitable for applications requiring high heat resistance and durability.
Types of Glass-Ceramics
Glass-ceramics vary based on composition and crystal structure. They can be tailored for high thermal shock resistance, and some forms, known as super heat-resistant crystallized glass, can endure extreme temperature changes and repetitive heating. In LED substrates, they are optimized for high output power across a wide range of wavelengths.
It’s essential to select the appropriate type of glass ceramics based on the specific application requirements.