Question

Cite the major differences in room temperature mechanical characteristics for metals and ceramics.

Answer 1

Ceramics are highly brittle materials with very high melting point. They are basically oxides or mitrides or carbides of metals. They are more heat and corrosion resistant than metals.

The atoms in ceramic materials are held together by a chemical bond. The two most common chemical bonds for ceramic materials are covalent and ionic. For metals, the chemical bond is called the metallic bond. The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. That is why, generally speaking, metals are ductile and ceramics are brittle.

These are materials held together by either type of bond will tend to fracture before any plastic deformation takes place. This gives catastrophic failures, as opposed to the normally much more gentle failure modes of metals.

For ceramics, the microstructure can be entirely glassy (glasses only); entirely crystalline; or a combination of crystalline and glassy.