C4-material choices

Question 1

what are composite materials?

Answer 1

materials that consist of 2 or more materials mixed together.

Question 2

factors to consider.

Answer 2

-cost
-durability
-environmental impact
-versatility
-aesthetic appeal

Question 3

what are the material classes?

Answer 3

-ceramics
-polymers
-metals
-composites

Question 4

why are ceramics useful?

Answer 4

-strong
-hard
but:
-weak in tension
-brittle

Question 5

why are polymers useful?

Answer 5

-flexible
-durable
-low density
but:
-they sent
-scratch easily

Question 6

why are metals useful?

Answer 6

-strong
-tough
-malleable
-conduct electricity
-high melting point

Question 7

what’s a young modulus?

Answer 7

-stiffness
-higher stiffer
-lower more flexible

Question 8

what is an alloy?

Answer 8

-a mixture of elements, including at least 1 metal.
-more useful than pure metals as they’re stronger.

Question 9

properties of mild steel.

Answer 9

-hard
-durable
-fairly strong
-malleable
-inexpensive

Question 10

properties of stainless steel.

Answer 10

-very resistant to corrosion.
-shiny appearance.

Question 11

properties of brass.

Answer 11

-malleable
-golden appearance

Question 12

properties of duralumin.

Answer 12

-fairly strong
-light weight
-malleable

Question 13

properties of alnico.

Answer 13

-magnetic

Question 14

properties of amalgam.

Answer 14

-low mpt.
-durable.
-inexpensive.

Question 15

why are alloys stronger than metals?

Answer 15

-due to their atoms being in an irregular pattern.
-different atoms, different sizes, harder to glide over.

Question 16

what are synthetic polymers?

Answer 16

-materials made by people.
-usually made from crude oil or natural gases.
-e.g. plastic, poly ethene, nylon, neoprene.

Question 17

what are polymers?

Answer 17

-long chain molecules.
-each link is formed by a smaller molecule called monomers.
-they connect to form a chain by a polymerisation reaction.

Question 18

examples of natural polymers.

Answer 18

-wool
-cotton
-leather
in the body:
-hair
-tendons
-bones
-haemoglobin
(all protein which is a polymer)

Question 19

what is addition polymerisation?

Answer 19

-monomers add together to form the long chains.
-the functional group in the monomers has a double bond.
makes the ethene molecule reactive.
-only product is a polymer, nothing is left over.

Question 20

what is condensation polymerisation?

Answer 20

-two monomers, react with each other and release water or alcohol.
-The reaction causes the monomers to bond together, forming a polymer.
-This process repeats itself many times, until it becomes a large, complex molecule.

Question 21

what is a polyamide?

Answer 21

-dicarboxylic acid
e.g.nylon used to make carpets and clothes.

Question 22

what is the size of a nano particle?

Answer 22

1 to 100nm

Question 23

what are fullerenes?

Answer 23

-Fullerenes are molecules of carbon atoms with hollow shapes.
-new allotrope of carbon was called the buckerminsterfullerene

Question 24

properties of graphene.

Answer 24

-high mpt/bpt
-good electrical conductivity
-very strong
-lightweight, flexible
-harder than diamond.

Question 25

what is corrosion?

Answer 25

happens when a metal continues to oxidise.
The metal becomes weaker over time, and eventually all of it may become metal oxide.

Question 26

what is rusting?

Answer 26

• corrosion of iron or steel using oxygen and water.

Question 27

how to prevent corrosion.

Answer 27

-barrier method.
-sacrificial protection.