What are ceramics?
The word ceramics is derived from the Greek word keramos which means ‘potter’s clay’. However, many compounds which are classified as ceramics today contain no clay.
Modern Ceramics can be defined as the compounds of metals and non-metals. They generally have ionic atomic bonding between them.
Traditional ceramics include insulating materials, glass, refractories, abrasives and enamels.
They include metal oxides, carbides, borides, nitrides and silicates. Some of their examples are Tungsten carbide, Silicon carbide, Beryllia, Zirconia, Alumina, Magnesia.
Advantages of ceramics
- Most of them have high hardness hence they are used as abrasive powder and cutting tools
- They have high melting point which makes them excellent refractory material
- They are good thermal insulators this is another reason to use them as refractory material
- They are high electric resistivity which makes them suitable to be used an insulator
- They have low mass density which results in lightweight components
- They are generally chemically inert which makes them durable
Disadvantages of ceramics
- They are brittle in nature
- They have almost zero ductility
- They have poor tensile strength
- The show a wide range in the variation of strength, even for the identical specimens
- They are difficult to shape and machine
Types of ceramics
They are mainly of two types based on their atomic structure.
- Crystalline ceramics
- Non-crystalline ceramics
They can also be classified into three different material categories.
Properties of ceramics
- High hardness
- High melting point
- Good Thermal insulator
- Highly electricity resistance
- Low mass density
- Generally, chemically inert
- Brittle in nature
- Zero ductility
- Low tensile strength
Examples of ceramics
- Barium titanate
- Bismuth strontium calcium copper oxide
- Boron oxide
- Boron nitride
- Lead zirconate titanate
- Magnesium diboride
- Sialon (Silicon Aluminum Oxynitride)
- Silicon carbide
- Silicon nitride
- Titanium carbide
- Uranium oxide
- Yttrium barium copper oxide
- Zinc oxide
- Zirconium dioxide
- Partially stabilized zirconia
Applications of ceramics
- They are used in space industry because of their low weight
- They are used as cutting tools
- They are used as refractory materials
- They are used as thermal insulator
- They are used as electrical insulator
Featured image attribution: By DLR German Aerospace Center – Ceramic materials being tested as a thermal storage medium, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=25662723