Ceramics, Composites and Polymers Flashcards
What does materials strength mean
Resistance of a material to an applied force
What does brittle mean
Snap easily
What are properties of ceramics
Hard
Brittle
Heat resistant
Corrosion resistant
How are ceramics made
Made by shaping then firing non metallic material at high temperatures where it hardens and sets
What are the 2 types of ceramics
Clay ceramics
Glass
Examples of clay ceramics
Brick
China
Porcelain
How are clay ceramics made
Shaping when wet
Heating
Hardens
Properties of clay ceramics
High compressive strengths
Types of glass
Soda lime glass
Brosilicate glass
What are the components of soda lime glass
Sodium carbonate
Silicon oxide
Limestone
Components of borosilicate glass
Sand
Boron trioxide
Which type of glass has a higher melting point
Borosilicate glass
Properties of glass
Transparent
Strong
Good thermal insulator (windows)
What are composites
2 or more materials with different properties combined to make a desirable material most are made from two components.
What are the two components of composite materials?
Reinforcement
The matrix
What is reinforcement?
Often long fires or fragments
What is the matrix
Find reinforcement together, usually start soft and hardens
What are polymers
Large molecules of high relative molecular mass.
links of smaller molecules called monomers
What do the properties of polymers depend on?
The monomers it was made from
conditions of the chemical reaction
Properties of polymers
Flexible
Easily shaped
Good insulators of heat and electricity
What are the conditions needed for low density polythene?
Moderate Temperature
High pressure
Catalyst
What are the properties of Low density polyethene ?
More flexible, but weaker
What are the uses for low density polyethene
Carrier bags
What are the conditions needed for high density polyethene
low temperature
Low pressure
Catalyst
What are the properties of high density polyethene?
More rigid but stronger
What are the uses for high density polyethene ?
Drain pipes
What are thermosoftening polymers?
Made up of lots of polymer chains held together by weak intermolecular forces
What happens when thermosoftening polymers are heated?
They break easily causing it to melt
What can you do to thermosoftening polymers after they have melted?
Can be remoulded into a different shape and hardened when cooled
What are Thermosetting polymers?
Made from lots of polymer chains held together by strong covalent bonds
What happens when thermosetting polymers are heated?
They require a lot of energy to break, so don’t soften when heated
Properties of thermosetting polymers
Hard
Strong
Rigid
Key difference between alloys and metals
Alloys are not malleable
Metals are malleable
