Mechanical Properties of Technical Ceramics
The most popular “superpowers” of CoorsTek technical ceramics are their mechanical properties. Advanced ceramic materials are engineered to outperform metals and polymers. High performance mechanical strengths include hardness, wear, rigidity, density, fracture toughness, and other application-specific mechanical requirements that often exceed steel, alloys, and plastics.
Mechanical Properties of Technical Ceramics
CoorsTek technical ceramics are known for their extreme hardness. Our materials are harder than every metal and naturally-occurring material known, except diamond. It’s not uncommon for ceramic components to extend wear life 10 to 100 times longer than conventional metals. The harder a material, the more resistant it is to localized permanent deformation from indentation or abrasion. We observe “macro” hardness on surfaces we see, but it is generally associated with strong intermolecular bonds at the “micro” level.
Advanced ceramics are highly rigid and do not bend easily. This means they provide exceptionally stiff, stable dimensional performance. In fact, CoorsTek ceramics deliver some of the highest stiffness-to-weight ratios for demanding, lightweight applications. Metals frequently warp, creep, or distort during machining or thermal cycling. Polymers tend to lose their shape under pressure, or even with aging. Flexural strength is a material’s effective strength under a bending load - a combination of compressive strength (being pushed together) and tensile strength (being pulled apart).
Density (Specific Gravity)
Technical ceramics are significantly lighter than high-strength metals, typically half the weight of comparable metal parts. Many transportation, aerospace, machinery, and armor applications benefit from lower mass. Lightweighting vehicles improves performance, increases fuel efficiency, and reduces energy costs over the lifetime of the vehicle. Reducing inertia in rotating equipment and machinery tools can dramatically reduce centrifugal forces – enabling higher speeds and longer life.
Some advanced ceramics are engineered to enhance toughness, the ability of a material to resist fracture. Fracture toughness measures the amount of energy a material can absorb before fracturing. Toughness tends to be larger for ductile materials like polymers and most metals, because both elastic (reversible) and plastic (irreversible) deformations allow these materials to absorb large amounts of energy. CoorsTek engineers ceramics for severe mechanical service environments with improved fracture toughness.
Other Mechanical Properties
Some applications have other specialized demands which require application-driven mechanical or physical properties including:
- Compressive Strength: A measure of a material’s ability to resist compression, a key value for structural design. Technical ceramics have exceptional compressive strength—greater than their tensile strength, so it is preferable to design assemblies in such a way that ceramic parts are in compression.
- High Temperature Strength: Many high performance applications require strength at high temperatures. Advanced technical ceramics retain the majority of their room temperature strength at high temperatures, and essentially revert to their original properties and dimension when returned to ambient temperatures. Learn more about the benefits of ceramics in high-temperature environments in our thermal properties section.
- Water Absorption and Gas Permeability: CoorsTek technical ceramics generally provide sealed performance, with no measurable water absorption or gas permeability. However, we can engineer application-specific materials which provide controlled levels of porosity or permeability.
- Poisson’s Ratio: This is a measurement of a material’s strain in the transverse direction when put under stress in the axial direction. CoorsTek technical ceramics exhibit a lower Poisson’s ratio than metals and polymers – meaning they keep their shape better when compressed or stretched. Like a rubber band, most materials tend to get thinner when stretched or thicker when compressed. Because technical ceramics generally have a lower Poisson’s Ratio than steel and polymers, there is little or no lateral expansion upon compression.
- Grain Size: Although grain size is not a direct measurement of performance, some material properties can vary with grain size. Up to a certain point, hardness increases with decreasing grain size in a ceramic material’s microstructure. Through vertical integration, CoorsTek engineers precise grain size control from ceramic material preparation through processing - assuring reliable, consistent performance.
Ceramic Materials with exception Mechanical Performance
Aluminum oxides (Al2O3) are known for their versatile combination of mechanical properties including good hardness, wear resistance, and flexural strength. CoorsTek Aluminas demonstrate excellent useful life-to-cost performance across a variety of industrial applications and are available in a range of purity levels and formulations. Generally the higher the purity, the more robust the mechanical performance.
Silicon carbides (SiC) are strong mechanical performers with exceptional hardness and rigidity at low density, valuable in applications which require a combination of light weight and mechanical strength. Some CoorsTek silicon carbides have extreme stiffness-to-weight ratios used when dimensional stability is critical.
Silicon nitrides (Si3N4) are distinguished by their high temperature strength, demonstrating an exceptional combination of mechanical and thermal properties. CoorsTek silicon nitrides are also used in severe-service environments requiring a combination of extreme flexural strength and toughness.
Zirconium oxides (ZrO2) are durable ceramics with exceptional fracture toughness. CoorsTek Dura-Z® and Technox® zirconias exhibit remarkable impact and fatigue resistance, frequently used in applications which require high performance mechanical strength with long-term endurance.
Applications Requiring High Performance Mechanical Properties
Are you looking for a material for to fit an application requiring high strength and high performance mechanical properties? Contact the CoorsTek team to begin discussing your application needs and requirements.
CoorsTek works directly with customers on custom specifications and designs for a wide range of applications. Advanced technical ceramic materials with strong mechanical properties are highly valuable in today’s industries.
Our ceramics are frequently used in the following industries and applications:
Automotive powertrain and propulsion systems frequently demand the mechanical strengths of technical ceramics to endure punishing conditions over the life of the vehicle, including components like fuel injectors, temperature sensors, and bearings. Combined with the benefits of light weight and high temperature performance, advanced ceramics are often the material of choice for critical components in both combustion and next generation vehicles.
Aerospace & Defense:
Many aerospace applications push the limits of material science, requiring flexural strength, rigidity, and low density to support mission-critical requirements for space mirrors, control systems, jet propulsion, and more. Ballistic armor for both soldiers and vehicles requires the ultimate combination of hardness and light weight for protection and mobility. CoorsTek advanced ceramics are both lighter and stronger than titanium or steel alloys.
Wear and erosion destroy conventional metals and polymers in harsh downhole environments. Oil & Gas OEMs and oilfield service providers choose technical ceramics to replace hardened alloys for components which get punished the most – including components like pump bushings, gas seal faces, ball valve assemblies, and frac plug buttons – reducing wear up to 100x, decreasing non-productive time (NPT), and improving output. From mining to wind turbine applications, CoorsTek technical ceramics are engineered to outlast the environment in wear tiles, chutes, hydrocyclones, and bearings.
Machinery & Equipment:
The latest machine tools and process equipment demand the precision, speed, and reliability provided by engineered ceramics with superior rigidity, durability, stability, and surface finish. CoorsTek ceramics are commonly used for bearings, bushings, fluid handling, and other components in machine tools spindles, roller guides, forming tools, and more.
In some of the highest precision processes on earth, chips with nanometer-scale circuitry are fabricated on silicon wafers. Handling these wafers requires stable, rigid, clean materials which also stand up to abrasion, cleaning, and non-stop processing. Semiconductor processing components including wafer chucks, chemical-mechanical polishing (CMP) plates, and lithography stages use CoorsTek technical ceramics to enable their technology advances.
Looking to Explore Further?
American Ceramics Society: Structure and Properties of Ceramics