What Are High-Temperature Insulating Materials?

What Are High-Temperature Insulating Materials?

High-temperature insulating materials include:

Polytetrafluoroethylene (PTFE) – an engineering plastic that can be used long-term within a temperature range of -195°C to 250°C. It is used for corrosion-resistant parts, wear-resistant and low-friction components, seals, and insulation parts.

Silicone Rubber – usable at temperatures between 100°C and 300°C. It is applied in high and low temperature resistant parts, insulation components, and pipe connectors.

Fluororubber – has an upper operating temperature limit of 300°C. It is used for chemical linings, high-grade seals, and high-vacuum rubber components.

Special Ceramics:

• Alumina (Al₂O₃) – offers high-temperature resistance, corrosion resistance, wear resistance, and excellent electrical insulation. It can be used up to 1600°C. Common applications include crucibles, high-temperature thermocouple sheaths, cutting tools, and molds.

• Silicon Nitride (Si₃N₄) – features excellent high-temperature strength, low thermal expansion, high thermal conductivity, and good thermal shock resistance. Although its usable temperature is lower than that of alumina, it retains high hardness at 1200°C and has good electrical insulation. It is typically used for mechanical seal rings, thermocouple sheaths, and gas turbine blades.

• Silicon Carbide (SiC) – known for its high strength at elevated temperatures, with a bending strength of 500–600 MPa at 1400°C. It is used in nozzles, furnace tubes, high-temperature bearings, and high-temperature heat exchangers.