Frequently Asked Questions
These are some of the most frequently asked questions people ask us. If you can’t find an answer on this page, please don’t hesitate to contact us.
What is Aluminum Nitride?
Aluminum Nitride (AlN) is an excellent material to use if high thermal conductivity and electrical insulation properties are required; making it an ideal material for use in thermal management and electrical applications. Additionally, Aluminum Nitride is common alternative to Beryllium Oxide (BeO) in the semiconductor industry as it is not a health hazard when machined. Aluminum Nitride has a coefficient of thermal expansion and electrical insulation properties that closely matches that of Silicon wafer material, making it an useful material for electronics applications where high temperatures and heat dissipation is often a problem.
What is Aluminum Nitride used for?
Aluminum Nitride (AlN) is an excellent material to use if high thermal conductivity and electrical insulation properties are required. Because of it’s qualities, it is an ideal material for use in thermal management and electrical applications. Some common applications of Aluminum Nitride include the following:
- Heat sinks & heat spreaders
- Electrical insulators for lasers
- Chucks, clamp rings for semiconductor processing equipment
- Electrical insulators
- Silicon wafer handling and processing
- Substrates & insulators for microelectronic devices & opto electronic devices
- Substrates for electronic packages
- Chip carriers for sensors and detectors
- Laser heat management components
- Molten metal fixtures
- Packages for microwave devices
What are technical ceramics?
Ceramics, defined by the broad definition of “inorganic solids”, are one of the main classes of materials, along with metals, polymers, and composites. There are several different types of ceramics, with technical ceramics (also known as engineered ceramics or advanced ceramics) being the group with the highest performing mechanical, electrical, and/or thermal properties. Their high performance is due in part to their extremely high purities which are most commonly metal compounds combined with oxides, carbides, or nitrides. Ceramics have the ability to increase product lifespan, increase efficiency, reduce overall maintenance costs, and improve performance.
What are the advantages of technical ceramics?
One of the most common properties of engineered ceramics is extreme hardness (& stiffness) – some are more than 4 times harder than stainless steel. This high hardness directly translates into excellent wear resistance, meaning that many technical ceramics have the ability to keep their precise, high-tolerance finish much longer than any other material.
Extreme Compressive Strength
Technical ceramics have very high strength, however, this is only when compressed. For example, many technical ceramics can withstand extremely high loads ranging from 1000 to 4000 MPa. Titanium on the other hand, which is regarded as a very strong metal, only has 1000 MPa of compressional strength.
Another common property of technical ceramics is their low density, ranging from 2 to 6 g/cc. This is significantly lighter than stainless steel (8 g/cc) and titanium (4.5 g/cc) with only the much softer aluminum being similar in density. Due to their high hardness and low weight, technical ceramics are increasingly being used in a variety of industries in applications where no other material can match their performance & long life.
Excellent Wear Resistance
Many technical ceramics are able to withstand incredibly high temperatures while still retaining their mechanical & electrical properties. Where all metals and polymers will start to compromise their properties, technical ceramics will continue to function with consistent performance and reliability. This property makes ceramics appropriate for use in very high temperature applications like furnaces, jet engines, brake systems, and cutting tools.
Excellent Electrical Properties
Technical ceramics tend to be excellent electric insulators (high dielectric strength). They are especially useful in high-temperature applications where other materials’ mechanical & thermal properties tend to degrade. Some ceramics have low electrical loss & high dielectric permittivity; these are typically used in electronic applications like capacitors and resonators. Additionally, the ability to combine an insulator with a structural component has lead to many product innovations.
Technical ceramics can function in situations where no metal (or nearly any other material) can maintain their properties. Some ceramics can operate in temperatures in excess of 1750°C, putting them in a class of their own as ultra-high-temperature materials. These ceramics have proven to be invaluable in high-temperature applications like engines, turbines, & bearings where they have increased the lifespan, performance, and efficiency.
Thermally Conductive or Insulative
Different types of technical ceramic materials have wildly varying thermal properties. There are some ceramics (Aluminum Nitride) that are highly thermally conductive and are commonly used as heat-sinks or exchangers in many electrical applications. Other ceramics are much less thermally conductive, making them suitable for a wide range of applications.
Chemically Inert & Corrosion Resistant
Technical Ceramics are very chemically stable and have low chemical solubility, making them highly resistant to corrosion. Metals and polymers cannot offer the same inertness or corrosion resistance, making ceramics a highly attractive option in many commercial and industrial applications, particularly when wear resistance is also needed.
What are the drawbacks of technical ceramics?
Poor Shear & Tensile Strength
With all of these advantageous properties, you may be wondering why we do not see technical ceramics more frequently. This is due to a variety of reasons, but mostly because other types of strength are tensile and shear; this is where technical ceramics strength can be 15 times less than those of metals.
Another issue that can arise with technical ceramics is that they can be very brittle due to their low ductility. This means that technical ceramics have very poor impact resistance. This property is caused by technical ceramics unique atomic bonds. Metals have “metallic” bonds which are relatively low strength, however, they can bond with atoms in any direction. This ability to have many multi-directional bonds is what makes metals ductile, tough, and relatively strong. Ceramics obviously do not have metallic bonds, instead they have ionic and covalent bonds – these are very strong, however they can only bond in very specific directions. This highly organized bonding structure means that it is difficult for the atomic structure to shift, making ceramics not malleable.
Difficult to Design
Every type of technical ceramic has specific thermal, mechanical, and electrical properties that can vary dramatically depending on the operating conditions & product design. In fact, even the manufacturing process of the exact same type of technical ceramic material can drastically change its properties.
Is Aluminum Nitride a ceramic?
Aluminum nitride (AlN) is a technical ceramic material that features an extremely interesting combination of very high thermal conductivity and excellent electrical insulation properties.
Is Aluminum Nitride toxic?
Exposure to AlN through mouth, inhalation, or injection may cause bone and lung toxicity. Repeated exposure can irritate the eyes and skin.
What's the difference between Macor vs Shapal?
Shapal Hi-M Soft and Macor glass ceramic are often compared because they both are machinable ceramics, however, both of these materials have significantly different mechanical and thermal properties. The following are som factors to consider when choosing between Macor and Shapal.
Shapal Hi-M is a thermal conductor at 90 W/(m K), Macor is a thermal insulator with a thermal conductivity of 1.46 W/(m K)
Shapal is not prone to suffering from thermal shock failures while Macor is vulnerable to thermal shock – if the parts have rapid heat up and cool down cycles then Shapal is a better option.
Shapal has a much higher maximum use temperature of 1900C (in an inert atmosphere) and 1000C (in air).
Shapal offers better bending strength (300 vs 94 MPa) as well as better compressive strength ( 1200 vs 345 MPa) when compared with Macor.
Macor is a cheaper material that Shapal Hi-M Soft, if it can be used instead of Shapal the user will typically see significant cost reductions.
What are the advantages of Shapal?
Shapal Hi-M Soft™ is a hybrid type of machinable Aluminum Nitride ceramic that offers high mechanical strength and thermal conductivity. By combining Aluminum Nitride with Boron Nitride, Tokuyama has created a ceramic that is easily machined into complex shapes while still keeping many of the advantages of traditional Aluminum Nitride. It features excellent machinability, high thermal conductivity and excellent mechanical strength which makes it suitable for a broad range applications. Some other benefits of Shapal include:
- Can be machined by a broad range of methods such as drilling, turning, milling to form complex shapes with high precision
- Excellent sealing ability to vacuum
- Approximately five times as much thermal conductivity as that of alumina (Aluminium Oxide)
- High mechanical strength & bending strength of 30kg/mm² is comparable to that of Alumina
- Excellent electric insulation
- Low thermal expansion
- Low dielectric loss
What can Shapal be used for?
Shapal Hi-M Soft™ is a hybrid type of machinable Aluminum Nitride ceramic that offers high mechanical strength and thermal conductivity. It features excellent machinability, high thermal conductivity and excellent mechanical strength which makes it suitable for a broad range applications, such as the following:
- Electronic components where electrical insulation and heat dissipation are required
- Components where low dielectric constant and dissipation factor are required
- Fixture parts where a low coefficient of thermal expansion is required
- Vacuum components
- Components where a low coefficient of thermal expansion required
- Heat sinks
- Crucibles for vacuum deposition
- Special refractory parts such as protective tubes
What's the difference between Shapal vs Aluminum Nitride?
Pure Aluminum Nitride is often the material of choice for high thermal conductivity applications, however, because it is such a hard material it is often costly to produce in small quantities or non-standard sizes. Shapal Hi-M soft is a machinable Aluminum Nitride/Boron Nitride composite material that can be machined into incredibly tight tolerances and complicated shapes while still providing excellent thermal conductivity.
What's the difference between Macor vs Alumina?
Alumina is a very commonly used technical ceramic due to its versatile properties, however, because it is such a hard material extensive diamond grinding is often required making it costly to produce in small quantities. Macor Machinable Glass Ceramic is often a viable alternative that can allows for significantly reduced production costs. The following are some factors to consider when choosing between Macor and Alumina.
Macor is vulnerable to thermal shock – if you have rapid heat up and cool down cycles Macor may not be appropriate. Shapal may be a viable alternative.
Macor has a maximum use temperature of 1000C (unstressed) and 800C (stressed); Alumina does offer higher temperature capabilities.
The same feature that makes Macor machinable means that it has relatively poor wear resistance when compared with Alumina.
For smaller quantities Macor often offers significant price reductions than Alumina components.
What is Macor made of?
Macor is a composite material made of fluorophlogopite (a type of Mica) in a borosilicate glass matrix (such as used in test tubes and Pyrex®) in a ratio of 45/55 respectively. The randomized microcrystalline structure allows tools to excavate micron-sized portions without cracking and fracture, leading to very exacting tolerances. Macor is composed of:
- 46% silica (SiO2)
- 17% magnesium oxide (MgO)
- 16% aluminium oxide (Al2O3)
- 10% potassium (K2O)
- 7% boron (B2O3)
- 4% fluorine (F)
What factors should I consider when using Macor?
Macor is vulnerable to halogen acids such as HCl (hydrochloric acid), although not a flash failure or sudden deterioration. Tests show a 2.52 gram sample (1cc) of Macor exposed to Hydrochloric Acid at a pH of 0.1 experienced a 100 mg loss, or 3.96% over 24 hours. Exposed to Sodium Hydroxide at a pH of 13.2 it experienced a loss of 0.396% in six hours. It is stable to 1000°C in air, and to 600°C in vacuum. Beyond 600°C (in vacuum) fluorine evolution will occur manifesting as boron trifluoride or hydrofluoric acid.
The most commonly available size of Macor is 12.5″ x 12.5″ x 2.125″ (317 x 317 x 54mm).
Can Macor be joined?
Macor can be connected and joined with a variety of methods. If it is metalized (metal inks or sputtering) it can be soldered, or brazed to other pieces, or bound to metal pieces such as titanium in the image to the right. Epoxy provides a strong joint and sealing glass provides a hermetic seal. Macor can even be lapped and bound with a convention mechanical connection. With its remarkably tight machining tolerances of up to 0.0005in (0.013mm), joining is a simple and straightforward task. It’s coefficient of thermal expansion readily matches most metals and sealing glasses. With appropriate polishing it can have a surface finish of less than 20 μinches, or 0.5 μmeters.
Is Macor good for prototyping?
Macor machinable glass ceramic is an incredibly versatile material that can quickly be made into very complex geometries. Because of it’s excellent machinability, Macor allows for rapid ceramic prototyping with many different iterations able to me made in a short period of time.
What is Macor Machinable Glass Ceramic used for?
Macor machinable glass ceramic was originally designed for NASA’s space shuttle to prevent thermal transfer from the exterior to the inside of the vehicle. It was used in the window frames of the space shuttle because of its electrical and heat insulating qualities; because of its radiation resistance and non-porosity (it has a porosity of zero); and because it emits no vapors (toxic or otherwise) of any kind, especially at the lower pressures that were found in spacecraft. Macor is an excellent material for high vacuum applications, such as electron microscopy, because when properly baked out, it cannot outgas at any achievable vacuum level.
Electronics / Semiconductors
- Precision coil formers (high precision and dimensionally stable)
- High voltage insulators (smooth surface finish and unaffected by arcing)
- Spacers, cavities and reflectors in laser assemblies (precision finish and heat resistant)
High Vacuum Applications
- Thermal breaks in high temperature processing equipment.
- Coil supports and vacuum feed-throughs (vacuum stable and hermetically sealable)
Aerospace / Space Industry
- Retaining rings on hinges, windows and doors of NASA’s Space Shuttle
- Supports and components in several satellite borne systems (thermally and electronically insulating)
- Fixtures and reference blocks in power generation units (dimensionally unaffected by irradiation)
What is Boron Carbide used for?
The combination of low specific weight, high hardness and reasonable toughness makes it a suitable material for body and vehicle armor. Boron carbide is also extensively used as control rods, shielding materials and as neutron detectors in nuclear reactors due to its ability to absorb neutrons without forming long lived radionuclide. As it is a p-type semiconductor, boron carbide can be a suitable candidate material for electronic devices that can be operated at high temperatures. Boron Carbide is also an excellent p-type thermoelectric material. Some typical applications of boron carbide include:
- Sand blasting nozzles
- Ball & roller bearings
- Wire drawing dies
- Body armour
What can Zirconia ceramic be used for?
- Wire forming/drawing dies
- Insulating rings in thermal processes
- Precision shafts and axles in high wear environments
- Furnace process tubes
- Wear resistance pads
- Thermocouple protection tubes
- Sandblasting nozzles
- Refractory material
- Extrusion dies
- Bushings and caps
- Kiln furniture crucible
- Fiber optic ferrules and sleeves
- Knives and blades
- Fuel cell parts
- Bearings & rollers
- Welding nozzles & pins
- Laser parts
- Gas igniters
- Electric insulator
- Ceramic guiders
- Oxygen sensors
- Medical and surgical component
- Mechanical seals
- Pumps, pistons, and liners
What's the difference between Yttria vs. Magnesia Zirconia?
While Y-PSZ is excellent for demanding mechanical applications, it may not be suitable for very high temperature applications because it suffers from grain boundary sliding; this occurs when prolonged exposure to heat causes the material to transform form the strong tetragonal phase to the weaker monoclinic phase. Similarly, it may not be suitable for warm and moist conditions since its properties deteriorate when it is exposed to water vapor. YSZ is therefore best suited when it is operating in dry and moderate temperature conditions. For more information on hydrothermal aging of Zirconia please contact us.
M-PSZ has better temperature and moisture resistant properties because it does not suffer from phase migration. M-PSZ maintains its strength even in moist high temperature environments where YSZ mechanical properties begin to deteriorate.
What are the properties of Zirconia?
The following are some general properties of Zirconia ceramic. For a full list and comparison of Zirconia properties, see our Zirconia properties comparison table.
- High density – up to 6.1 g/cm^3
- High flexural strength and hardness
- Excellent fracture toughness – impact resistant
- High maximum use temperature
- Wear resistant
- Good frictional behavior
- Electrical insulator
- Low thermal conductivity – aprox. 10% of Alumina
- Corrosion resistance in acids and alkalis
- Modulus of elasticity similar to steel
- Coefficient of thermal expansion similar to iron
What is Zirconia ceramic?
Zirconia is a very strong technical ceramic with excellent properties in hardness, fracture toughness, and corrosion resistance; all without the most common property of ceramics – high brittleness. Unlike traditional ceramics that tend to be hard and brittle, Zirconia offers high strength, wear resistance, and flexibility far beyond those of most other technical ceramics.
There are several grades of Zirconia available, the most common of which are Yttria Partially Stabilized Zirconia (Y-PSZ) and Magnesia Partially Stabilized Zirconia (Mg-PSZ). Both of these materials offer excellent properties, however, the operating environment and part geometry will dictate which grade may be suitable for specific applications (more on this below). Its unique resistance to crack propagation and high thermal expansion make it an excellent material for joining ceramics with metals like steel. Due to Zirconia’s unique properties it is sometimes referred to as the “ceramic steel”.
What is Silicon Carbide used for?
Silicon Carbide has properties remarkably similar to those of diamond – it is one of the lightest, hardest, and strongest technical ceramic materials and has exceptional thermal conductivity, resistance to acids, and low thermal expansion. Silicon Carbide is an excellent material to use when physical wear is an important consideration because it exhibits good erosion and abrasive resistance, making it useful in a variety of applications including the following:
- Valve seats
- Sliding bearings
- Mechanical seals
- Seal rings (water ring pumps)
- Wear parts (thread guides)
- Kiln furniture crucibles
- Blast nozzles
- Heat exchangers
What is Silicon Nitride used for?
- Rotating ball bearings & rollers bearings
- Cutting tools
- Engine components: valves, rocker arm pads, seal faces
- Induction heating coil supports
- Turbine blades, vanes, buckets
- Welding & brazing jigs
- Heating Element components
- Metal tube forming rolls and dies
- TIG / Plasma welding nozzles
- Weld positioners
- Precision shafts and axles in high wear environments
- Thermocouple sheaths & tubes
- Semiconductor Process Equipment
What is Alumina used for?
Alumina is a very hard ceramic and is excellent at resisting abrasion. It is ideal for wear-resistant inserts or products. Alumina is commonly used as a high temperature electrical insulator, particularly the higher purity grades which offer better resistivity. Alumina also offers good resistance to strong acids and alkalis at elevated temperatures and is ideal for applications where resistance to corrosive substances is required. Some common applications of Alumina include:
- Electronic components & substrates
- High temperature electrical insulators
- High voltage insulators
- Laser tubes
- Machine components
- Mechanical seals
- Precision shafts and axles in high wear environments
- Roller and ball bearings
- Seal rings
- Semiconductor parts
- Shot blast nozzles
- Thermocouple tubes
- Tap plates
- Valve seats
- Wear components
- Wire and thread guides
- Ballistic Armor
What are the advantages of Alumina?
Alumina, also known as Aluminum Oxide, is a hard wearing advanced technical ceramic material frequently used in a wide variety of industrial applications. It features high hardness and wear resistance, low erosion levels, high temperature resistance, corrosion resistance, and bioinertness. Additionally, it can be highly polished making it useful for precision sealing applications like pumps and pistons. Alumina is an excellent high temperature ceramic material due to its high temperature stability. It is the most commonly used type of advanced ceramic and is available in purities ranging from 95 – 99.9%.
Some of the key advantages of Alumina include:
High Temperature Ability – Alumina can be used in both oxidizing and reducing atmospheres up to 1650°C (2900°F) and in vacuum environments up to 2000°C (3600°F).
Abrasion Resistant – Alumina is a very hard ceramic and is excellent at resisting abrasion. It is ideal for wear-resistant inserts or products.
Electrical Insulator – Alumina is commonly used as a high temperature electrical insulator, particularly the higher purity grades which offer better resistivity.
Chemical Resistance – Alumina offers good resistance to strong acids and alkalis at elevated temperatures and is ideal for applications where resistance to corrosive substances is required.
Additional properties and advantages of Alumina include
- High hardness
- Wear & abrasion resistant
- High compressive strength
- High mechanical Strength
- Resists strong acid and alkali attack at high temperatures
- Excellent electrical insulation properties
- Decent thermal conductivity
What is Boron Nitride used for?
Boron Nitride is available in virtually any custom shape that can be machined and has unique characteristics and physical properties which make it valuable for solving tough problems in a wide range of industrial applications.
- Break rings for continuous casting of metals
- Continuous casting
- Crucibles and containers for high purity molten metals
- Deck plates
- Heat treatment fixtures
- High temperature lubricant
- High temperature valves
- High temperature & high voltage electrical insulatorsInduction heating coil supports
- Laser Nozzles
- Molds/mold release agent
- Motel metals and glass casting
- Nozzles for transfer or atomization
- Nuclear Shielding
- Radar components and antenna windows
- Refractory applications
- Vacuum furnace supports which require electrical resistivity
What is Boron Nitride?
Boron Nitride (BN) is an advanced synthetic ceramic material available in solid and powder form. Its unique properties – from high heat capacity and outstanding thermal conductivity to easy machinability, lubricity, low dielectric constant and superior dielectric strength – make boron nitride a truly outstanding material.
In its solid form, boron nitride is often referred to as “white graphite” because it has a microstructure similar to that of graphite. However, unlike graphite, boron nitride is an excellent electrical insulator that has a higher oxidation temperature. It offers high thermal conductivity and good thermal shock resistance and can be easily machined to close tolerances in virtually any shape. After machining, it is ready for use without additional heat treating or firing operations.
In inert and reducing atmospheres, the AX05 grade of Boron Nitride grades will withstand temperatures over 2,000°C. It is commonly used as an insulator in contact with tungsten and graphite electrodes at those temperatures.
Do you supply or work with other materials that are not listed on your website?
Precision Ceramics is unusual as we offer the full range of technical ceramics from machinable grades like Macor and Shapal through to materials that require diamond grinding like alumina, zirconia, carbides and nitrides. We can machine and supply virtually any ceramic material – please contact us with your specific requirements for more information. Our goal it to optimize the material selection and design for the customer, rather than what is right for our capability.
Can you help me with material selection and design of ceramics?
Yes we can. We have a competent team of technical sales staff with many years’ experience that can help you chose the right material. Whether it is for wear, thermal management, electrical properties, or something else, we can help you by designing an appropriate component for ceramic manufacture from simple suggestions to more complex solutions. Contact us with details of your application and one of our engineers will be happy to help you.
Are you willing to sign a Non-Disclosure Agreement for confidential projects?
Precision Ceramics works with many organizations to develop projects that may be confidential or sensitive in nature. We have an established record of working with our customers to ensure that the highest level of privacy is maintained for confidential projects.
Can I machine the ceramics myself?
The harder ceramics like alumna and zirconia will require diamond tooling but other materials like Macor and Shapal can be machined. To get the right result it does take time, experience and semi-specialized tooling but it can be done and many of our customers take advantage of this when they need extremely fast solutions in-house.
Can I get a sample or purchase a small quantity?
Yes, we are happy to supply small samples of material for you to test. We can also supply prototype quantities through to volume production to suit your needs.
What is the maximum size of Macor I can purchase?
300mm x300mm x 55mm is the maximum size and we can supply any smaller size or shape on request. We also carry many standard sizes of Macor bar, rod and sheet in stock for quick delivery. We are happy to discuss supplying fully machined components produced in our in-house facility. A thickness of 60mm may be possible in some applications.
What is the maximum size of Shapal I can purchase?
We have recently been able to increase the maximum size availability of Shapal to 300mm x 300mm x 64mm. We carry many standard sizes of Shapal in stock and can supply fully machined components or non-standard sizes on request.
What is the maximum working temperature of Macor?
Macor begins to soften at 1,000°C so for continuous use we would recommend a maximum working temperature of 850’C. We have other ceramics that can be used under load at over 2,000°C.
What is the maximum working temperature of Shapal Hi-M Soft?
Shapal can be used at temperatures up to 1,900°C in an inert atmosphere and up to 1,000°C in an oxidizing atmosphere. Click Here for further information.
Do you have a minimum order value?
No, we are happy to cater to any size project.
Do you ship internationally?
Yes we can ship to virtually anywhere in the world. Typically we will use FEDEX Express or we can also arrange shipments on your own courier account if you prefer to take this route.
How long will it take for you to send me a quote?
This depends totally on the complexity of your requirements. For simple items such as bars and rods, we can generally supply a quotation within 48 hours. For more complex items, we should be able to respond within 3 to 4 days. If you have any other specific question on any of our products or services, please contact us.
What is the name of AL2O3?
Al2O3 is the chemical formula for Aluminium oxide, which is a chemical compound of aluminium and oxygen. It is commonly called alumina.
What are the advantages of Silicon Nitride?
Compared with other technical ceramics, its low thermal expansion coefficient provides good thermal shock resistance. It is extremely hard, surpasses the high temperature capabilities of most metals and also has a superior oxidation resistance. As a consequence, silicon nitride can withstand the toughest conditions in the most demanding high temperature, high-load applications.
Even NASA scientists recognized its unique properties when silicon nitride bearings were used in the main engines of the Space Shuttle. It was identified as one of the few monolithic ceramic materials capable of surviving the severe thermal shock and thermal gradients generated in hydrogen / oxygen rocket engines and proved completely reliable throughout the entire Space Shuttle program.
What is the formula for Silicon Nitride?
The formula for silicon nitride is Si3N4.