Man-made Composites

Question 1

What are composites?

Answer 1

Combinations of two or more materials
-> a matrix phase
-> a reinforcement phase
- particles
- short fibres
- long fibres

Question 2

What is the aim of composites?

Answer 2

To have the best properties of each constituent material with few/none of their disadvantages

Question 3

What are some examples of fibre-reinforced composites?

Answer 3

These materials are commonly implied by the term composite:
- Glass fibre reinforced polymers (GFRP)
- Carbon fibre reinforced polymers (CFRP)
wood is a natural fibre-reinforced composite

Question 4

What are some advantages of fibre-reinforced composites?

Answer 4

Still, end up with lightweight but a lot more stiffer

Question 5

What are particulate composites?

Answer 5

Concretes (aggregates, rebar), particulate composites:
- cement -> high hardness ceramic carbides in ductile material
-> e.g. WC in Co
- used in cutting tools
- WC has high hardness
- Co prevents crack propagation
- Dispersion strengthened metals -> smaller volume of particulate

Question 6

What are some examples of filled polymers?

Answer 6

• sand
• silica flour
• glass particles
• as noted previously -> filled polymers have increased stiffness and abrasion resistance
  -> may also reduce the price

Question 7

What are some examples of lamellar composites?

Answer 7

• often wood-based
• plywood, glulam etc