Mechanical Properties
Mechanical properties describe how a ceramic material behaves when subjected to external forces.
Hardness indicates a ceramic surface’s resistance to indentation and scratches. Ceramics are generally very hard. Hardness units : HV or GPa.
Mass per unit volume, units: g/cm³. It affects the overall weight and compactness of the ceramic component.
A measure of a material’s resistance to crack propagation. It characterizes the fracture resistance of a material. Units : MPa.m1/2
The ability to withstand being compressed or crushed. Ceramics often have very high compressive strength. Units : MPa.
The ability of a material to resist fracture under bending load, also known as modulus of rupture. It is crucial for the reliability of ceramics in structural applications. Units: MPa
The ratio of stress to strain within the elastic range of a material, indicating its stiffness. A high modulus means the material is rigid and deforms less under load. Units: GPa
The maximum stress a material can withstand while being stretched before failing. Ceramics typically have lower tensile strength compared to their compressive strength. Units : MPa.
The ratio of transverse contraction strain to axial extension strain when a material is stretched. It describes how a material deforms in directions perpendicular to the direction of loading. No units
Thermal Properties
Thermal properties describe how a material responds to changes in temperature.
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Maximum Service Temperature- (℃)
The highest temperature at which a material can be used continuously in air without significant degradation. Ceramic materials can often withstand very high temperatures. -
Thermal Shock Resistance -(ΔT(℃))
The ability to withstand rapid temperature changes without cracking. This is crucial for components subjected to rapid heating or cooling. -
CTE (Coefficient of Thermal Expansion)-(10-6/K@ 25°C – 400°C)
The rate at which a material expands per degree of temperature change. A low CTE means the material is dimensionally stable with temperature changes. -
Thermal Conductivity-(W/m.k@ 25°C)
The ability to conduct heat. High thermal conductivity aids heat dissipation, while low is good for thermal insulation. -
Specific Heat-( 103J/(kg·K))
The amount of heat required to raise the temperature of a unit mass by one degree. It influences how quickly a material heats up or cools down.
Electrical Properties
Electrical properties determine how a material behaves in an electric field and are crucial for electronic applications.
Measures a material’s ability to store electrical energy in an electric field. A high dielectric constant is desirable for capacitors.
Energy loss in a dielectric material under an alternating electric field, converted to heat. Low loss is critical for high-frequency applications.
The maximum electric field a material can withstand without electrical breakdown. It indicates the effectiveness as an insulator.
Measures how strongly a material opposes the flow of electric current. A high value indicates a good electrical insulator.
Related Materials
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Alumina ceramics are advanced ceramics with excellent comprehensive properties, and they were researched early, are the most widely used, and are the most mature.
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Zirconia ceramics are second only to alumina ceramics in terms of applicability and are very important advanced ceramics for structural applications.
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Aluminum nitride ceramics are advanced ceramics with high thermal conductivity and insulation, and are often used in electronic packaging substrates and heat dissipation components.
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Silicon nitride ceramics are high-strength, lightweight, and thermally shock resistant advanced ceramics commonly used in bearings and turbine components.
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Boron nitride ceramics are advanced ceramics with excellent self-lubricating properties, high-temperature insulation and heat dissipation, and machinability.
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Silicon carbide ceramics are advanced ceramics with semiconductor properties and resistance to high-temperature corrosion, making them suitable for power devices and high-temperature structural components.
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Steatite ceramics are low-cost, high-frequency insulators, and have low mechanical strength, making them suitable for use in general equipment parts.
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The machinable ceramics have excellent machinability and can be machined using traditional metalworking tools.
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Cordierite ceramics have ultra-low thermal expansion and are resistant to thermal shock, making them suitable for use as catalyst carriers and thermal insulation materials.
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Mullite ceramics are resistant to high temperatures and have low thermal expansion, making them suitable for use in kiln furniture and refractory materials.
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ZTA ceramics combine the hardness of alumina with the toughness of zirconia, making them suitable for cutting tools and wear-resistant components.
A Quick Guide From Ceramic Material Properties to Applications
We have some industry experience regarding the relationship between the performance of ceramic materials and the application of products, which can serve as a quick and simple reference for you when designing solutions.
1.For structural components subjected to high loads: focus on fracture toughness, flexural strength, and compressive strength.
2.For high-temperature or thermal cycling environments: maximum operating temperature, thermal shock resistance, and coefficient of thermal expansion (CTE) are key considerations.
3.For electronic insulation and packaging: prioritize evaluation of electrical properties such as dielectric strength, volume resistivity, and dielectric constant/loss.
4.For thermal management components: thermal conductivity is the most critical parameter, and it must be considered in conjunction with CTE( Coefficient of Thermal Expansion) to match other materials.
Hardness values can be used as a preliminary design consideration for projects, with high hardness representing excellent wear resistance and dimensional stability. When your components face friction, particle erosion, or need to maintain precise tolerances, choosing high-hardness ceramics (such as alumina and boron nitride) is key to extending their service life.
For high thermal conductivity ceramics, aluminum nitride (AlN), beryllium oxide (BeO), or high-purity silicon carbide (SiC) are preferred. The key is not only the thermal conductivity value, but also evaluating:
1. Whether the coefficient of thermal expansion (CTE) matches that of adjacent materials (such as chips or metals) to reduce thermal stress;
2. Whether the electrical insulation properties (volume resistivity, dielectric strength) meet requirements;
3. Machinability and cost. For example, aluminum nitride is an excellent overall heat dissipation substrate material, while beryllium oxide has the best thermal conductivity but is limited by toxicity.
The importance of fracture toughness depends on the failure mode and load type.
Scenarios where fracture toughness is more important: Materials may have microcracks or defects (common in ceramics), or are subjected to impact loads or thermal cycling. It determines the material’s ability to resist crack propagation, directly affecting reliability and service life.
Scenarios where flexural strength is more important: Structural components mainly bear static or continuous bending loads, and the material is homogeneous, dense, and defects are controllable. It determines the initial failure strength of the component under load.
Core principle: During the design phase, safety design based on fracture toughness should be prioritized to prevent catastrophic fracture; then, process control should be used to ensure sufficient flexural strength to meet load-bearing requirements. Both must be evaluated together.
Jinghui offers professional material selection consulting services. Please provide your application environment, key requirements, and performance targets, and our engineering team will recommend the most cost-effective ceramic solutions for you.