Metals

Question 1

Name the stock forms of ferrous metals…

Answer 1

Sheet, bar, tube and angle

Question 2

What is a ferrous metal?

Name 2 qualities…

Answer 2

Ferrous metals are iron based metals
#1 Magnetic
#2 Rust

Question 3

What happens as you increase the carbon content of iron?

Answer 3

The higher the carbon content the more brittle and hard it becomes.

Question 4

Mild steel;
What percent is carbon?
What are it's properties?
What are it's positives?
What are it's negatives?

Answer 4

Carbon; 0.25%
Properties; Ductile, tough, soft (can be bent)

+ (relatively) Easy to work
- Rusts easily (more than other steels)

Question 5

What are possible uses of mild steel?

Answer 5

Car body panels
Nuts and bolts
White goods

Question 6

Medium carbon steel;
What percent is carbon?
What are it’s properties?
Can it be tempered?

Answer 6

Carbon; 0.5%
Properties; quiet ductile
It can be tempered
(It’s an Engineers favourite)

Question 7

What are possible uses of Medium carbon steel?

Answer 7

Springs

Question 8

High carbon steel;
What percent is carbon?
What are it’s properties?
Can it be tempered?

Answer 8

Carbon; 1.5%
Properties; not very ductile
It can be tempered

Question 9

What are possible uses of High carbon steel?

Answer 9

Carpentry tools

Question 10

Cast iron;
What percent is carbon?
What are it’s properties?
What are it’s negatives?

Answer 10

Carbon; 3.5%
Properties; not ductile, hard (inflexible), brittle
Shatters when dropped

Question 11

What are possible uses of cast iron?

Answer 11

Vices
Clamps
Engines

Question 12

What is a non-ferrous metal?

What are 2 basic qualities?

Answer 12

A metal that contains no iron
#1 Non magnetic
#2 Doesn't rust

Question 13

Aluminium;
What does it come from?
Properties?
Positives?
Negatives?

Answer 13

Origin; bauxite (difficult to extract)
Properties; malleable, ductile, very conductive (heat & electricity), light, self protects

+ 100% recyclable (melts 660oc)
- Expensive, has to be extracted using electrolysis

Question 14

What are possible uses of aluminium?

Answer 14

Aircraft, expensive car bodies and castings (add silicon)

Question 15

Copper;
Properties?
Positives?

Answer 15

Malleable, ductile, very conductive (heat and electricity)

+non toxic

Question 16

What are possible uses of copper?

Answer 16

Plumbing

Question 17

Give some positives and negatives of Gold, Silver and Platinum…
What are possible uses?

Answer 17

+ Non corrosive
+ Hypo-allergenic
-Expensive
(Gold; very good conductor)

Jewellery
(Gold can also be used for SIM cards)

Question 18

Zinc;
Properties?
Uses?

Answer 18

Has a low melting temperature; 850^, non corrosive

Plating for ferrous metals

Question 19

Stock forms of non-ferrous metals?

Answer 19

Sheet, tube and ingot

Question 20

What metal can be used for white goods?

Answer 20

Mild steel (also used for car bodies & nuts and bolts)

Question 21

What metals could be used to make a ring?

Answer 21

Gold, platinum and silver

Question 22

Why high carbon steel used in carpentry tools?

Answer 22

Very hard (1.5% carbon) it can be sharpened to a very sharp edge

Question 23

What metal can be used to make springs?

Answer 23

Medium carbon steel (0.5% carbon)

Question 24

Why might a clamp break when dropped?

Answer 24

It is made from cast iron which is 3.5% carbon so is very brittle and not ductile; shatters

Question 25

Why is copper used for pluming?

Answer 25

It is malleable; pipes need to be bent, and is non toxic

Question 26

What might be used to plate the outside of a ferrous metal? And why?

Answer 26

Zinc; it is non corrosive so protects the ferrous metal which would rust

Question 27

Why would you use mild steel for a car?

Answer 27

Mild steel is a malleable material which means it can be press formed into the shape required. It can also be spot welded; which is one of the main ways of constructing car body panels.
Mild steel sheet will crumple not shatter; crumple zones.
You can also apply variety of finishes for aesthetics.

Question 28

Why would you use Aluminium in a drinks can (4)

Answer 28

It is malleable; allows the can shape to be cupped and deep drawn in production. It’s also available in thin sheet form for punching the blank shape.
Aluminium is a non-toxic material (chemical resistant) won’t contaminate the drink.
It’s low melting point, makes it easy to recycle.
It’s widely available which is required for mass
production.

Question 29

How would you finish a car? (what finishes literally)

Answer 29

Galvanise, prime, undercoat, overcoat, lacquer

Question 30

What 2 ferrous metals can you temper?

What is tempering?

Answer 30

Medium carbon steel & high carbon steel

Heating the metal to a controlled temperature and quenching in a controlled liquid (usually oil)

Question 31

What is annealing?

Answer 31

Heating the metal then naturally letting it return to it’s original state

Question 32

What is hardening?

Answer 32

Heating the metal until red hot then instantly quenching

Question 33

What does it mean to work harden?

Answer 33

The more you hit the metal the harder it gets

Question 34

Ferrous metals rust, non ferrous metals…

Answer 34

Oxidise; self protecting!

Question 35

Why is copper used as electrical wiring

Answer 35

Copper is be used in the production of
electrical wiring, as it is a very good electrical conductor.
Copper is extremely ductile, meaning it can be drawn into a wire without fracture.

Question 36

What is galzanising?

Answer 36

The application of a coat of zinc