Metals

Question 1

What is a ferrous metal? What are some basic properties of them?

Answer 1

They are iron based metals which are magnetic and rust.

Question 2

What happens as you increase the carbon content of iron?

Answer 2

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

Question 3

Give some positives (4) and some negatives (1) of Mild Steel and examples of it in use (2). What is it’s carbon content?

Answer 3

\+ Relatively cheap
\+ Ductile
\+ Soft
\+ Tough 
- Rusts
Car bodies and white goods (fridges etc)
Carbon steel content: 0.25%

Question 4

Give some positives (3) of Medium Carbon Steel and examples of it in use (1). What is it’s carbon content?

Answer 4

\+ Quite ductile
\+ A little hard
\+ Can be tempered
Springs
Carbon steel content: 0.5%

Question 5

Give some positives (3) of High Carbon Steel and examples of it in use (1). What is it’s carbon content?

Answer 5

\+ Quite hard
\+ A little ductile
\+ Can be tempered
Carpentry tools
Carbon steel content: 1.5%

Question 6

Give some positives (2) and some negatives (1) of Cast Iron and examples of it in use (3). What is it’s carbon content?

Answer 6

\+ Not ductile 
\+ Hard
- Brittle
Vices, clamps and engines
Carbon steel content: 3.5%

Question 7

What is a non-ferrous metal? What are some basic properties of them?

Answer 7

A metal that contains no iron. They are non-magnetic and do not rust.

Question 8

Give some positives (6) and some negatives (1) of Aluminium and examples of it in use (2). What ore does it come from?

Answer 8

\+ Malleable
\+ Ductile
\+ Very conductive of heat and electricity
\+ Light
\+ Self protects
\+ 100% recyclable
- Expensive, due to electrolysis
Aircraft and castings (with silicon)
Comes form bauxite

Question 9

Give some positives (5) of Copper and examples of it in use (1).

Answer 9

\+ Non-toxic
\+ Malleable
\+ Ductile
\+ Very conductive of heat and electricity
\+ Connected together easily
Plumbing

Question 10

Give some positives (3) and some negatives (1) of Gold, Silver and Platinum and examples of it in use (2).

Answer 10

\+ Excellent electrical conductor (Gold)
\+ Non-corrosive
\+ Hypo-allergenic
- Expensive
Jewellery and sim cards (Gold)

Question 11

Give some positives (2) of Zinc examples of it in use (1).

Answer 11

+ Low melting point
+ Non corrosive
Plates ferrous metals

Question 12

What is an Alloy?

Answer 12

An alloy is a mixture of two or more metals to get the best proprieties of the base metals.

Question 13

Give some positives (3) and some negatives (1) of Dualumin and examples of it in use (1). Is it ferrous or non ferrous and what is it made from?

Answer 13

\+ Very high strength
\+ Very light (lighter than aluminium)
- Very expensive
Used in structural components of aircraft
It is a non ferrous alloy
4% copper and 95% aluminium

Question 14

Give some positives (3) of Bronze and examples of it in use (3). Is it ferrous or non ferrous and what is it made from?

Answer 14

\+ Easy to work
\+ Easy to cast
\+ Self lubricating
Sculpture, coins and bearings
It is a non ferrous alloy
Copper and zinc

Question 15

Give some positives (3) of Stainless Steel and examples of it in use (3). Is it ferrous or non ferrous and what is it made from?

Answer 15

\+ Tough
\+ Wear resistant
\+ Corrosion resistant
Sinks, Cutlery and Prison toilets
It is a ferrous alloy
Steel 80% Chrome and nickel 20%

Question 16

Give some positives (3) of High Speed Steel and examples of it in use (1). Is it ferrous or non ferrous and what is it made from?

Answer 16

\+ Very hard
\+ Can be sharpened to a very sharp edge
\+ Will cut when hot
Cutting tools
It is a ferrous alloy
Steel, Tungsten, Molybdenum, Chromium, Cobalt, Aluminium

Question 17

Describe extrusion.

Answer 17

Metal is put in a hopper which places it into a tube which pushes them into an archimedean screw. This then takes them though a heater which makes it molten. The metal is extruded though a simple dye and then cooled. This is an infinite process which is cut to length.

Question 18

Describe blanking.

Answer 18

Sheet metal is placed onto the machine. A punch then comes down on the metal and pushes its shape out of the metal though the die, to form a blank.

Question 19

Describe press forming.

Answer 19

Sheet metal is clamped over a female mould a former then comes down onto it forming the shape of the female mould. This is only good for relatively shallow shapes like car bodies.

Question 20

Describe cupping.

Answer 20

When a punch pushes a metal sheet into a die to make a cylindrical cup like shape.

Question 21

Describe deep drawing.

Answer 21

An object made by cupping is placed on a slightly smaller dye so when the punch pushes it down the metal is made thinner.

Question 22

Describe embossing.

Answer 22

Sheet metal is clamped over a female mould a former then comes down onto it forming the shape of the female mould. Similar to press forming but is more intricate and shallow, makes quality street lettering on tines.

Question 23

Describe spinning.

Answer 23

A metal sheet is clamped onto a lathe like machine, next to the mandrel. whilst spinning the sheet is pushed onto the mandrel to make the shape. You can tell if an object is formed like this if it has radial marks. Makes deep and tapered shapes.

Question 24

Describe casting sand.

Answer 24

Used for ferrous metals. Green sand is placed in a cope and drag (two parts of the mould) a model of the object is made placed in the sand to make a mould cavity (has a runner and riser to pour metal in which are cut of after cooled). The metal is then poured into the runner to fill the cavity. This cools and the object is formed. The objects have a sandy texture and the mold has to be re made each time.

Question 25

Describe die moulding.

Answer 25

Used for non ferrous metals. A plunger pushes molten metal from a chamber though a nozzle into the cavity in a die. This then cools and the die is taken apart, the object is ejected by ejector pins. Very much like injection molding.