Important Mechanical and Physical Properties of Ceramics

The ceramic materials are generally glassy or ionic. Usually, they fracture before tension efforts and exhibit elasticity as they have a tendency to be porous materials. The microscopic blemishes and pores act similar to resist concentrating efforts.

Ceramic materials show artificial deformations. However, due to the rigidity, , there are very few systems of slides for dislocations and the deformation happens in very slow form during structure & crystalline mechanism. In the glassy materials, the viscous smoothness is the principal reason of the plastic deformation. On the other hand, it is absent in many applications of ceramic substances.

These ceramics have high resistance to the firmness and are proficient of operating in high temperatures. Thermal conductivity ceramic has  a property that determines how easily the heat is transferred in the ceramic material, they have high thermal conductivity resistance. Great hardness makes them a substance widely used like cutting tools and as abrasive. The ceramic materials are more resistant than metallic materials, but its thin structure prevents them from being slithery, basic mechanism for a classic deformation.

Ceramic materials like metals  have the same crystalline imperfections (crevices and small cracks), which tends to concentrate the efforts and due to which the metallic material fail by fracture.

Physical properties of Ceramics are as follows:

• Low electrical conductivity.
• Low thermal expansion and failure.
• Low thermal conductivity.
• Less weight than metals, but more than the polymers.

The structure of ceramic crystals contains many atoms of different sizes. It is the most complex of all structures of different materials. The bonds between these atoms are usually ionic (bonds made between oppositely charged ions) or covalent (sharing of electrons, hence they make strong bonds). These bonds are much stronger than metallic bonds.

The properties like hardness, thermal or electrical resistance, are considerably higher in ceramics than in metals.

The ceramics are widely available as a single crystal in polycrystalline form with lots of grains.

The grain size has a main control on the properties and the resistance of ceramics. The finer the grain size (fine ceramics), the higher the toughness and resistance.

The important properties of ceramic materials are:

• Mechanical resistance: The requirement usually refers to the compressive strength and modulus of elasticity magnitudes closely related to the porosity. It likewise noted the acceptable tensile strength of ceramic material.
• Density and porosity: They are all defined as similar to the natural stones. The actual density is about 2g/cm3.
• The ability to receive low temperatures without suffering damage in the faces exposed to cold.
• Color and Appearance: The color depends on the impurities (iron oxide) and additives that are used for the purpose of ornament in the building.
• Absorption: is called the specific absorption% by weight of water absorbed on a dry piece and its permeability.