PROPERTIES OF CEREMIC


CHEMICAL PROPERTIES
-stable over long period of time
-more resistant to corrosion
-generally do not react with acid, alkalines, gases, liquids
-high melting point
-can be heated up to its boiling point

MECHANICAL PROPERTIES
-strong, resilient, resistant to temperature
-bend strength determines strngth of ceremic
-considerable stifffness under compression and pressure
-one of stronger ceremic: zirconium dioxide
-bend strength comarable to steel
-zirconias retain temperature up to 900 degrees
-silicon carbide and silicon nitrate retain up to 1400 degrees
-used for gas-turbine engines
-brittle, breaks when dropped, break when heated and cooled quickly

-PHYSICAL PROPERTIES
-extremely srong
-light metals as strong as heavier metal parts
-less dense then semimetal
resist wear and abrasion
-alumionium oxide and silicon carbide are extremely hard
-used to cut, sand, grind, polish metals and other materials
-one of the hardest material: diamond made from carbon

THERMAL PROPERTIES
-high melting point
-resist deformation and retain strength under high temperature
-sudden and large temperature change weaken ceremic
-silicon nitrate and silicon carbide expand more and contract less under high temperature than other ceremics
-used to make rotors of jet planes
-can withstand great vibrations in temperature

ELECTRICAL PROPERTIES
-chromium dioxide conducts electricity
-aluminium oxides does not conduct
-act as insulator
some ceremics do not conduct well, act as semi conductors
-conduct electricity more than insulators
-porcelain: act as insulator at low temperature and conducts electricity at high temperature

MAGNETIC PROPERTIES
-ceremics containing iron oxides are called ferrites
-has magnetic properties comparable to nickel and iron
-other nmagnetic ceremics contain oxides of barium, maganise, nickel
-used in motors and electric circuit
-can be manufactured with high resistant to demagnetized