Question

Write short notes on the essential differences and underlying causes in the thermal and mechanical properties of polymers, metals, and ceramics.

*very simply..!! Thank you

Answer 1

Metals
This type of materials has characteristics like, high electrical and thermal conductivity, the ability to be deformed or cut into new shapes without breaking, and high mechanical strength. Since metals must be reduced from chemical compounds, they tend to be somewhat more costly than non-metallic materials, and they are often vulnerable to corrosion damage as the metals react with their environment to re-form those compounds. They tend to be shiny and malleable. Metals have these characteristics because they have nonlocalized electrons.

Ceramics
Ceramics are generally compounds between metallic and nonmetallic elements and include such compounds as oxides, nitrides, and carbides. Typically they are insulating (not electrical or thermally conductive) and resistant to high temperatures and harsh environments (corrosion resistant). They usually have lower electrical and thermal conductivity, higher stiffness, good resistance to corrosive environments, and lower fracture toughness than metals.

Polymers are generally organic compounds based upon carbon and hydrogen. They are very large molecular structures. Usually they are low density and are not stable at high temperatures. They can be readily formed into complex shapes. Their strength, stiffness, and melting temperatures are generally much lower than those of metals and ceramics. Their light weight, low cost, and ease of forming make them the preferred material for many engineering applications.