Materials - Metals

Question 1

What categories can metals be divided into?

Answer 1

Non ferrous
Ferrous
Alloy

Question 2

What makes aluminium quite corrosion resistant?

Answer 2

It oxidises quickly, the coating of aluminium oxide is clear, colourless, and non-staining. Stops air, water and chemicals reaching the metal.

Question 3

What is anodization?

Answer 3

an electrochemical process that converts the metal surface into a decorative, durable, corrosion-resistant, anodic oxide finish.

Question 4

What can aluminium conduct?

Answer 4

It conducts heat and electricity very well.

Question 5

Aluminium is both d_______ and m__________.

Answer 5

Ductile and malleable.

Question 6

When aluminium is polished it is ___________ ______________.

Answer 6

Highly reflective.

Question 7

Aluminium has the highest ________________________ of any metal.

Answer 7

Strength-to-weight ratio.

Question 8

What happens to the strength of Aluminium as temperature rises?

Answer 8

It reduces.

Question 9

What is an environmental benefit of aluminium?

Answer 9

It can be very easily recycled and is 100% recyclable.

Question 10

What are the reasons Aluminium is commonly used in foil?

Answer 10

It is impermeable and odourless.

Question 11

What are some disadvantages of aluminium?

Answer 11

It is difficult to weld which limits the ways it can be joined together.
Not very hard.

Question 12

Advantages of copper

Answer 12

Good conductor of both heat and electricity
Very malleable and ductile
Corrosion resistance
Tough

Question 13

Disadvantages of copper

Answer 13

Poor tensile strength
Not very hard - scratches

Question 14

Advantages of silver.

Answer 14

Very malleable
Ductile
Good conductor of both electricity and heat
Anti bacterial
Attractive

Question 15

Disadvantages of silver

Answer 15

Soft and scratches easily
Not very corrosion resistant, tarnishes quickly

Question 16

What is pewter 90% made up of?

Answer 16

Tin

Question 17

Advantages of pewter

Answer 17

Malleable
Non-elastic
Easily fusible with other metals
Non-corrosive so water-tight

Question 18

Why is pewter excellent for coating other metals such as in production of cans for preserving food?

Answer 18

Does not impart flavour to the food and doesn’t leech chemical into food content

Question 19

Disadvantages of pewter

Answer 19

Soft and not hardwearing
Dents easily
Low mp
Low strength
Expensive to mine and extract

Question 20

Advantages of stainless steel

Answer 20

High corrosion resistance
Heat and fire resistant
Easy to clean - non reactive to cleaning chemicals
Good strength to weight ratio
High tensile strength

Question 21

Disadvantages of stainless steel

Answer 21

Scratches and dents
Difficult to weld
High initial cost

Question 22

Advantages of brass

Answer 22

High corrosion resistance
Ductile and malleable
Easily worked
Attractive
Good flow characteristics - casts well and takes detail
Reasonable conductor
Antimicrobial properties

Question 23

Disadvantages of brass

Answer 23

Still fairly expensive
Scratches

Question 24

What are the different types of steel heat treatments?

Answer 24

Tempering
Annealing
Work Hardening
Normalising

Question 25

What is tempering?

Answer 25

The heat process used to increase the toughness of iron-based alloys.

Question 26

Advantages of tempering

Answer 26

Helps to relieve stress making the metal easier to weld or machine. Increases strength while making the material more flexible and ductile. Increases hardness and introduces wear-resistant properties to the surface or through entire metal.

Question 27

Disadvantages of tempering

Answer 27

Time consuming Inconsistent hardness Discolouration Limited control over mechanical properties

Question 28

What is annealing?

Answer 28

The heat treatment process that changes the physical and sometimes chemical properties of a material to increase ductility and reduce hardness to make it more workable.

Question 29

Advantages of annealing

Answer 29

Increase workability Increases ductility Increases toughness Reduces hardness

Question 30

Disadvantages of annealing

Answer 30

Can cause defects Needs temperature control while cooling down Time consuming Can alter the properties of the material

Question 31

What is work hardening?

Answer 31

The process by which a materials load-bearing capacity increases during plastic deformation.

Question 32

Advantages of work hardening

Answer 32

High impact strength Increases toughness

Question 33

Disadvantages of work hardening

Answer 33

Lower ductility More brittle

Question 34

Where is tempering used?

Answer 34

In tools, springs and structured steel

Question 34

Where is annealing used?

Answer 34

In machining tools

Question 35

Where is work hardening used?

Answer 35

Mining chutes, conveyors, grizzlies, screens, bucket lips

Question 36

Advantages of duralumin

Answer 36

Strong Hard Lightweight Malleable Machines well

Question 37

What is duralumin made up of?

Answer 37

95% aluminium 4% copper 0.5% manganese 0.5% magnesium

Question 38

Disadvantages of duralumin

Answer 38

Not very corrosion resistant Soft - can bend easily

Question 39

Where is duralumin used?

Answer 39

Aircraft, speedboat and automobile frames, pressure cookers

Question 40

Advantages of bronze

Answer 40

High thermal and electrical conductivity Corrosion resistance Hard Tensile strength Resistant to metal fatigue

Question 41

Disadvantages of bronze

Answer 41

Susceptible to "bronze disease" Hard to work with