Ceramics are essentially inorganic solids (organic ones are polymers) that are also not metals.
So in addition to what is usually thought as “ceramics”, glass, diamond and graphite are classified as ceramics. The sapphire used as watch crystals is also a ceramic. Engineering wise, ceramics are divided into four sections. Among these “engineering ceramics” are what we will cover today.
The rest of the three sections are what we know as ceramics in daily life i.e. tableware, bricks, tiles, etc. Engineering ceramics themselves have many classes and it is not possible for us to cover them all in such an article.
Thus we will talk about their general properties and advantages. Unlike earthenware (which is comparatively brittle), engineering ceramics are made of very pure materials. These pure ingredients ensure the needed properties can be produced consistently. Usually the ingredients are oxides, carbides, nitrides etc. Most of which are compounds of metals with oxygen, nitrogen, carbon or others.
|XY Ceramic Property|
|Modules of Elasticity||Gpa||200||210||220||210||220|
|Thermal Expansion Coefficient||10-6K-1||11||10||10||10||10|
|Thermal Shock Resistance||△T.℃||400||400||400||400|
|Maximum Use Temperature|
in Oxidizing Atmosphere
|Max Use Temperature|
in Reducing or Inert Atmosphere
|Volume Resistivity at 20℃||Ωcm||10^13||10^12||10^12||5X10^13||10^12|