Design Features

Material Properties

Color

Zirconium oxide insulation tubes are typically white, a characteristic typical of ceramic materials.

Density

The density of zirconia insulation tubes is approximately 6 g/cm³, resulting in high material compactness, which enhances their wear 

resistance and high-temperature resistance.

Zirconium Oxide Content

The main component of this insulation tube is zirconia, with a content of 94.40%, ensuring excellent high-temperature resistance and 

chemical stability.

Air Permeability and Water Absorption

Zirconium oxide insulation tubes have zero air permeability and 0% water absorption, indicating extremely low gas permeability and 

moisture absorption, making them suitable for high-temperature and high-pressure environments.

Grain Size

The grain size is approximately 0.5 μm, indicating a fine-grained structure, which contributes to improved strength and hardness.

Mechanical Properties

Rockwell Hardness and Vickers Hardness

The zirconia insulation tube exhibits a Rockwell hardness (R45N) of 78 and a Vickers hardness (500g load) of 11.5 GPa (1175 Kg/mm²), 

indicating high hardness and wear resistance.

Flexural Strength and Compressive Strength

At 20°C, the insulation tube achieves a flexural strength of 800 MPa and a compressive strength of 2000 MPa, demonstrating excellent 

mechanical strength and compressive properties.

Elastic Modulus and Fracture Toughness

Its elastic modulus is greater than 200 GPa, and its fracture toughness is 9 MPa·m¹/², indicating high rigidity and impact resistance.

Thermal Properties

Thermal Conductivity

The thermal conductivity of the zirconia insulation tube is approximately 2.5 W/(m·K) in the range of 20°C to 400°C, classifying it as an 

insulating material and contributing to stable temperature operation at high temperatures.

Coefficient of Thermal Expansion

Its coefficient of thermal expansion is 9.6 × 10^-6/℃, indicating that it has a certain degree of thermal expansion, but it is relatively small, 

which helps to reduce thermal stress during thermal cycling.

Thermal Shock Resistance

Zirconium oxide insulation tubes exhibit excellent thermal shock resistance, with a thermal shock temperature difference reaching 250℃, 

indicating that they can maintain stable performance in working environments with rapid temperature changes and are not prone to 

thermal cracking or breakage.

Application areas

Zirconia heat-insulating tubes, due to their excellent high-temperature performance and chemical stability, are widely used in the following 

fields

Metallurgical industry: 

Used as heat-insulating tubes in high-temperature melting furnaces to improve furnace temperature stability and 

thermal efficiency.

Glass industry: Used as rolls or heat-insulating tubes in glass melting furnaces to resist the corrosion and abrasion of high-temperature glass.

Ceramics industry: 

Used as rolls in ceramic forming machines to improve the production efficiency and quality of ceramic products.

With its excellent physical and mechanical properties, as well as its stable performance in high-temperature environments, zirconia 

heat-insulating tubes have become an indispensable material in high-temperature industrial fields.