Properties, Classification And Finishing Operations of Technical Ceramics

Ceramics in the broad definition of “inorganic solids” are one of the most important classes of materials next to metals, polymers, and composite materials. There are different types of ceramics, with technical ceramics (also known as engineering ceramics or high-performance ceramics) being the group with the highest mechanical, electrical, and/or thermal properties. Its high productivity is partly due to its extremely high purity, most of which are metal compounds combined with oxides, carbides, or nitrides. Ceramics can extend product life, increase efficiency, reduce overall maintenance costs, and increase productivity.

Technical Ceramic Material Group

Many groups of technical ceramics are available on the market today, but the basic classification defines them as highly effective components made of strong inorganic compounds. At the chemical level, they are usually held together by high-strength covalent bonds that form a strong structural lattice. The outstanding thermomechanical and chemical properties are maintained to the semi-crystalline microstructure and finally converted into solid monolithic ceramics.

technical ceramics

Multi-Lab supplies a wide range of high performance engineered ceramic materials including:

• Silicon Nitride (SiAlON): At Multi-Lab, we specialize in silicon nitride derivatives known as Sialons, outstanding universal engineering ceramics with fine-tuning
• Zirconium (ZrO2): With its incomparable durability, technical ceramics based on zirconium oxide are perfect for wear-resistant applications, from dentistry to metal forming.
• Aluminum (Al2O3): The technical ceramic of the same name, aluminum trioxide, belongs to the group of oxide ceramics and is the most used technical ceramic worldwide.
• Silicon carbide (SiC): With exceptional thermomechanical and non-corrosive features, technical ceramics based on silicon carbide are fitting for use in the chemical industry.

Read More – Applications of Technical Ceramics in Manufacturing Processes

Properties of Technical Ceramics

Chemically Inert and Corrosion Resistant

Technical ceramics are chemically very enduring and have moderate chemical solubility, which causes them extremely resistant to corrosion. Metals and polymers cannot allow the same inactivity or corrosion protection, making Macor or Machinable glass ceramics a very attractive option in several business and industrial applications, particularly when corrosion resistance is also needed.

High Hardness

One of the main general features of technical ceramics is their unusual hardness- some more than 3 times harder than stainless steel. This unusual hardness is instantly shown in its outstanding corrosion resistance, which indicates that several technical ceramics can manage their precision coatings with high endurance longer than other elements.

Excellent Wear Resistance

Many technical ceramics resist very high temperatures while preserving their construction and electrical qualities. When all elements and polymers start to decline, engineering ceramics will proceed to run with steady production and safety. These properties make ceramics suitable for use in very high-temperature applications such as ovens, jet engines, braking systems, and cutting tools.

Low density

Another common property of technical ceramics is their low density of 2 to 6 g/cm³. It is notably thinner than stainless steel (8 g/cc) and titanium (4.5 g/cc), with only the much more delicate aluminium having a comparable frequency. Due to their immense hardness and moderate density, technical ceramics are frequently being utilized in an extensive type of industries in applications where no other element can balance their production and strength.

Incredible Compressive Strength

Technical ceramics have very high strength, but these are only available under pressure. Many technical ceramics, for example, can withstand very high loads of 1000 to 4000 MPa. On the other hand, titanium, which is considered a very strong metal, only has a compressive strength of 1000 MPa.

Conductive or Thermal Insulation

Different types of technical ceramics have very different thermal properties. There are several ceramics (aluminum nitride) that have high thermal conductivity and are often used as radiators or exchangers in many electrical applications. Other ceramics are extremely less thermally conductive and are consequently suitable for a broad variety of applications.

Fasteners used for High Temperature Application

The fasteners are the most significant parts of the hardware group. They are extensively used to fix two physically different specifications. For most purposes, fasteners are made out of common elements like stainless steel sustain more than enough. However, other applications particularly those that require extreme temperatures, need special kinds of fasteners. Such fasteners are made of metals that show the sorts of resistance that is needed to endure severe environments. Some fasteners can beat threaded ceramics screws and bolts when it comes to resisting heat, stress, and destructive environments. The following are three categories of high-heat fasteners:

Fasteners Used for High Temperature Application from Multi-lab.co.uk

Nickel Alloy Fasteners

The term alloy relates to the material which is formed of two or more than two metals. For example, stainless steel is a metal made of iron, nickel, chromium and several other components. Different alloys hold different features with concerns to properties like melting point and corrosion stability. When fastening components in high-temperature situations is needed, alloys usually prove to be effective as they contain larger amounts of nickel. These types of alloys perform to present greater stability to oxidation, which can happen more easily at high temperatures. Oxidation relates to a chemical response that creates iron-containing elements to form rust and other applications of corrosion. Nickel alloys maintain high-temperature durability ratings more than that of simple stainless steel.

Refractory Metal Fasteners

Refractory metal fasteners are stronger than nickel alloys as nickel alloys cannot resist the extreme heat produced inside specific types of furnaces. When it comes to maintaining temperatures above 2,000 degrees Fahrenheit, such refractory elements need to be used. These metals maintain melting circumstances thousands of degrees which is higher than regular metals such as steel. Refractory alloys include elements such as niobium, molybdenum, rhenium tantalum, and tungsten. The unbelievable features of such metals are available at a great value. Moreover, to allowing especially high melting points, these elements also exceed in terms of hardness and consistency.

Ceramic Fasteners

Indeed, refractory metals do not have the perfection of holding the greatest resistance to heat. That guarantee comes into the class of ceramic fasteners. These may be made of one of two elements such as alumina and zirconia. Alumina fasteners allow heat resistance of up to 3000 degrees Fahrenheit. While Zirconia fasteners can allow even higher, with temperature ranges of as much as 4350 degrees Fahrenheit. This quality makes ceramic fasteners the most reliable fasteners when it comes to high-temperature uses.      

Special Properties of Machinable Glass Ceramics

Macor is a problem-solving material combining the properties of technical ceramics. Machinable Glass Ceramics/Macor is a matrix of borosilicate glass stacked with fluorphlogopite mica containing roughly as follows … .. Silica 46%/MGO 17% Al2o3 16% with the equilibrium comprised of Potassium Oxide/Boron Trioxide and Fluorine! fitting a wide range of uses.

machinable glass ceramics

1. It is an excellent insulator.
2. Opaque white material.
3. Low Thermal Conductivity
4. Polishable
5. Easily Machinable
6. It exhibits zero porosity.
7. No Outgassing
8. Radiation Resistant
9. Electrical Insulator
10. Strong and Rigid
11. Hold tight Tolerances

High Performance Plastic

Plastic is a material that we can found anywhere in different forms. It has a wide range of industrial and consumer applications. The moulding capacity of this material makes it suitable for a wide range of functions. But, how high-performance plastics make them different from normal plastic. Have a look:

High performance plastic is a polymer which is used for applications in the aerospace, chemical, and nuclear field due to its high thermal stability, superior mechanical properties. These are often used to replace metals due to their lesser weight and corrosion resistance. It is difficult to process high performance plastic and it requires specialized machinery.

Machinable Glass Ceramics

Macor Machinable Glass Ceramic

Macor Machinable Glass Ceramics is comprised of Fluorphlogopite mica in a Borosilicate glass lattice with a white appearance like that of aluminous porcelain, however can be machined in customary ways fundamentally the same as that of metal machining, including boring, tapping and screw cutting, and so on.

All about Silicon Carbide (SiC) and Silicon Carbide Ceramic

Silicon carbide is one of the most used material in several high-tech applications. SiC includes a useful combination of mechanical properties, widely used abrasives and architectural material. It has great hardness, chemical inertness, stability to abrasion and oxidation at temperatures over the melting position of steel restrict it for use under many high-temperature conditions including seals and valves, rocket nozzles and wire dies and more. Silicon carbide’s applications use its superior wear and erosion stability. Because of thermic and steal resistance properties, SiC discovers its applications in high-temperature electronics and temperature exchanger pipes. Many heating components are also made of silicon carbide.

Typical silicon carbide components are:

• High strength
• Low density
• Excellent high-temperature strength
• Oxidation stability
• Superior thermal shock resistance
• High hardness and wear endurance
• Outstanding chemical resistance
• Low thermal increase and high thermal conductivity

Standard silicon carbide applications involve:

• Hardened and moving turbine elements
• Ball valve parts
• Wear plates
• Seals, bearings, pump vanes
• Kiln furniture
• Heat exchangers
• Semiconductor wafer processing facilities

Now coming to silicon carbide ceramics, these are hard elements available in black colour and have high strength. Silicon carbide ceramics are used for manufacturing of objects that are constrained to extreme mechanical damage and notably high temperatures. These ceramics have the ability to maintain mechanical energy at the great temperature of 1400 C. Silicon carbide ceramics are extensively utilised in various manufacturing industries like nuclear power, machine building, and metal.

Read More – Things To Consider While Choosing Efficient Technical Ceramics

Silicon carbide ceramics can be produced using either a reaction bonded method or sintered method. The foremost method to produce ceramics which are based on silicon carbide is high-temperature sintering of silicon carbide particles with different binding additives.

Take a look at the most popularly used examples of ceramics and the method of their preparation:

• Silicon Nitride Bonded: This is manufactured from a blend of silicon carbide granules and silicon involving a nitrogen environment at a temperature under the melting spot of Silicon.
• Direct Sintered: The sponge-like element is manufactured using silicon carbide powder, including additives of boron and aluminium, different binding factors and carbon-containing additives.
• Reaction Bonded: It is produced by using granules silicon carbide with the nice powder of silicon and graphite.
• Composite Bonded: Fine powder of pure silicon carbide is blended with silicon and restraining element. Nitrogen environment is required to be heated at a temperature above 1350 C.

The advantages of silicon carbide ceramics are the same as the silicon carbide material.