Thermal Properties of Technical Ceramics
Technical ceramics outperform other materials—like metals and alloys—in applications where extreme high- or low-temperature conditions require products that can perform without failing through expansion and contraction, melting, or cracking. Ceramics cover a wide-array of applications where temperature strength, precision, and thermal resistance are key to operational success and safety.
Thermal properties characterize how a material reacts to changes in temperature. Many of our technical ceramics are ideal for specific thermal performance, including high- and low-temperature precision applications, by controlling the inherent material properties and structure. Many technical ceramic formulations can be tailored to fit application-specific thermal requirements, where thermal conductivity, coefficient of thermal expansion, and thermal shock resistance are critical.
Thermal Properties of Technical Ceramics
Thermal conductivity measures how well a material spreads heat within itself. Cooking pans have high thermal conductivity allowing evenly distributed heat to pass quickly into the food. On the other hand, insulative gloves are used to handle hot objects because their low thermal conductivity prevents heat from transmitting to sensitive hands. Technical ceramics are extraordinarily versatile, exhibiting a wide range of thermal conductivity. With over 400 technical ceramic formulations in the CoorsTek portfolio, we will work with you to find the optimal material for your application.
Coefficient of Thermal Expansion (1X10-6/°C)
The coefficient of thermal expansion defines how much a material expands or contracts based on external temperatures. Most materials swell with the application of heat because the energy causes the atoms to move more rapidly, stretching their bonds. Ceramics generally have a low coefficient due to their strong interatomic bonds, making them more stable across wide temperature ranges.
Specific Heat (J/kg*K)
Specific heat measures how easy or difficult it is to raise the temperature of a product. In high-temperature applications, where regulating temperature is critical, this measurement shows what products will perform the best. Ceramics have exceptional performance when it comes to high specific heat requirements, outperforming steel.
Thermal Shock Resistance (°C)
Thermal shock resistance measures the ability to withstand dramatic and sharp temperature changes. During rapid cooling, the core of the product remains while the surface cools, preventing uniform thermal contraction. Many technical ceramic formulations display high thermal shock resistance, meaning they minimally expand or contract during extreme or rapid temperature changes.
Ceramic Materials with High Thermal Performance
Aluminas (aluminum oxide, Al2O3) are the most commonly used technical ceramics with good all-around performance CoorsTek has engineered over 100 aluminas used across a wide variety of applications with thermal resistance of 1500 °C or more. Zirconia Toughened Alumina is a specialized alumina designed for high thermal shock resistance and increased toughness.
Aluminum Nitride – High Thermal Conductivity:
Aluminum Nitrides combine high thermal conductivity with strong electrical resistance. They are an excellent solution for many electronic applications— allowing electrical systems to dissipate heat quickly for maximum efficiency.
Quartz – Thermal Shock Resistance and Thermal Expansion:
Synthetic quartz or fused silica (silicon oxide, SiO2) exhibits excellent thermal shock resistance due to extremely low thermal expansion and extreme purity. These unique properties and thermal stability allow this technical ceramic to be used in rapid thermal processing applications.
Silicates – Thermal Shock Resistance:
Silicate ceramics are multi-phase materials developed from natural silicate sources such as clay, kaolin, feldspar, and soapstone. Today’s silicates are useful for technical applications such as electrical insulators and chemical labware.
Silicon Carbide – Thermal Stability
Silicon Carbides (SiC) exhibit high hardness, wear resistance, corrosion resistance, and strength at high temperatures. CoorsTek has engineered a variety of silicon carbide processes and compositions which deliver properties and features optimized for specific application requirements.
Silicon Nitride – High Temperature Strength & Endurance:
Silicon Nitrides (Si3N4) have a unique grain structure which delivers high strength and toughness, along with exceptional thermal shock resistance. This material is ideal for applications with high dynamic stresses, thermal rigor, and demanding reliability requirements.
Zirconia – High Heat Resistance
Zirconias have a unique crystal structure which combines excellent strength, high fracture toughness, wear resistance, and high temperature resistance. Some zirconias have engineered crystal structures which expand when a micro-crack is formed, arresting crack growth and preventing brittle failure. These materials are ideal for extreme mechanical environments, particularly impact prone applications.
Applications Requiring Exceptional Thermal Performance
Are you looking for a material for your high-temperature application? Contact the CoorsTek team to begin discussing your application needs and requirements.
CoorsTek technical ceramics experts work directly with customers - engineering custom designs across a wide range of applications. Advanced technical ceramic materials with excellent thermal performance are highly valuable in many of today’s high-tech industries.
Our ceramics are frequently used in the following industries and applications:
Aerospace & Defense:
Aerospace engine components and propulsion systems require technical ceramics that can deliver high-performance thermal properties needed for the most demanding requirements in aircraft engines and advanced propulsion systems. Our Cerbec® balls and bearings use the exceptional thermal strength and endurance of silicon nitride materials that other materials can’t match. Additionally, advanced technical ceramic tubes and rods are used in investment casting to form vanes on aircraft turbine engines requiring high-temperature performance properties.
Silicon carbides are engineered and optimized for applications demanding thermal stability, such as flight control components. These materials are ideal for mirrors and structural components for ground or space-based optical systems requiring pixel-scale thermal stability in a wide-range of temperatures.
Fluid control system components used in aircraft valves, seals, and hydraulic components require the high-performance properties of technical ceramics, including high-temperature performance, to meet the severe-service conditions of engines and control systems.
Technical ceramics are used in many aerospace and defense applications
because of their superior thermal properties, including supersonic
and hypersonic applications.
Cerbec® bearing balls and rolling elements, with their ability to operate at higher speeds and temperatures, are ideal for fuel injection systems EV motor shafts in automotive applications. With minimal thermal expansion, these bearings outperform their counterparts made of steel.
Igniters made with technical ceramics are used in a wide variety of everyday household applications like furnaces, ovens, and stoves.
Consumer & Household:
Ceramic heating components are designed to maximize performance, efficiency, and reliability. These components are engineered for long useful life and excellent thermal stability, including high operating temperatures, low thermal expansion rates, and superior thermal shock resistance.
As a long-time expert in ceramic igniters, we provide reliable, long-life ceramic igniters for hot surface ignition. Our DuraGlo™ igniters are used in gas heating systems, ovens, ranges, dryers and other applications requiring technical ceramics with high-performance thermal properties.
Thermal management needed for high-brightness LEDs and HID lighting is achieved through the superior thermal performance and translucent parts made from our technical ceramics. Technical ceramic phosphors and substrates are used in LED manufacturing.
When it comes to HID arc tubes, we have deep expertise in developing and producing high-volume translucent ceramics for this application. Our polycrystalline alumina materials combine high translucency with the thermal stability needed for the brightest and most demanding lighting.
Machinery & Equipment:
Technical ceramics are used in a wide range of heavy-duty, hard face seal components for a variety of applications including centrifugal pumps, compressors, and turbomachinery where precision tolerances are required for high-speed operation where friction causes excessive wear (see Mechanical Properties) and high temperatures. Each hard face seal is manufactured to withstand thermal expansion and conductivity to ensure they maintain their shape and performance.
Power Generation, Utilities, Steel Mills, and Other Processing Plants:
Electrostatic insulator applications require the advanced material properties of engineered ceramics. Many of these insulators are used in high-temp applications like open hearth and oxygen furnaces in steel mills. Because our technical ceramics have a high specific heat threshold, they outperform many traditional materials, including steel and other metals. Every ceramic produced by CoorsTek is manufactured from raw material through the finished product, ensuring the reliability of the components are the best in the industry.
DuraPure® high-purity alumina ceramic is the insulator material of choice for high temperatures during prolonged periods where material strength and volume resistivity need to be maintained. Our technical ceramics are used in a wide range of environmentally regulated industries such as power generation, pulp and paper mills, wood products mills, chemical processing plants, steel mills, oil refineries, and incineration plants.
Pictured: An electrostatic insulator component used in power generation/utility applications.
Engineered technical ceramics are used in the semiconductor industry because of their excellent thermal performance in combination with other material properties. Specifically, ultra-pure, technical ceramics provide the thermal protection necessary through the whole cycle of semiconductor wafer processing and fabrication. Conventional furnaces and other rapid thermal processing (RTP) equipment used during manufacturing require materials to withstand temperatures up to 1200°C.
High-purity advanced ceramics providing exceptional thermal shock resistance and stability are ideal for semi wafer processing applications including deposition, diffusion, and epitaxial growth. Advanced technical ceramics are especially critical when it comes to single crystal pulling for semiconductor applications. Crucibles using our ceramics are able to withstand prolonged high temperatures and thermal shock that occur during manufacturing.
Looking to Explore Further?
See our Material Comparison Tool to compare multiple ceramic materials to see which may be the best one for your particular application.
Of course, you can also contact us with your questions.
American Ceramics Society: Structure and Properties of Ceramics