Zirconia Ceramic Tubes: High-Temperature Insulation and Wear Protection Where Alumina Reaches Its Limits

Why Zirconia Outperforms in the Toughest Duty Cycles

Zirconia (ZrO₂), typically stabilized with 3 mol% yttria (3Y-TZP) or magnesia, offers a property combination no other engineering ceramic matches:

• Fracture toughness of 6–10 MPa·m½ — two to three times higher than alumina, giving outstanding resistance to cracking under mechanical shock and thermal cycling

• Maximum service temperature up to ~2,000°C in suitable atmospheres, with low thermal conductivity (2–3 W/m·K) that makes zirconia an excellent insulating barrier

• Extremely low thermal expansion mismatch issues — its CTE (~10×10⁻⁶/K) is close to steel, a decisive advantage in metal-ceramic assemblies

• Chemical inertness against molten metals, slags and most acids and alkalis, supporting long life in foundry, plating and chemical process lines

• Low friction, mirror-finish surfaces (Ra < 0.1 µm achievable by grinding) for plungers, bushings and metering components

Typical Applications

• Thermocouple protection tubes and insulators in heat-treatment furnaces

• Molten-aluminum and molten-steel contact parts: riser tubes, ladle nozzles, degassing rotors

• High-temperature heating-element supports and kiln furniture pins

• Wear-resistant liners, guide tubes and pump shaft sleeves in slurry handling

• Insulating barriers in oxygen sensors and solid-oxide fuel-cell stacks

What to Specify When Ordering

To quote accurately, define: stabilizer grade (3Y-TZP for strength, Mg-PSZ for thermal-shock duty), OD/ID and wall thickness (small bores down to 1 mm are producible), length, concentricity and straightness tolerances, surface finish (as-fired vs centerless-ground), and the operating atmosphere and peak temperature. Freceramic supports both prototype quantities and volume production with CNC green machining before sintering and precision grinding after.

About Freceramic

Yixing Furui'en Special Ceramics Co., Ltd. manufactures zirconia ceramic tubes, rods, sheets, alumina and corundum components, ceramic substrates and cordierite products. The company holds ISO 9001 certification, and its materials have passed EU pollution-free testing. Send your drawing or specification via the contact page for a fast technical review and quotation.