Metals

Learning Intention:Show a working knowledge of various metals

Metal Ores

Ores are naturally occurring rocks that contain metal or metal compounds.

Pure metals and Alloys

• Metals are rarely used in their pure form. They are usually mixed with other metals to improve their properties. This is called an alloy

aluminium, copper, iron, lead, zinc, tin,silver and gold

Ferrous and Non-ferrous MetalsNon-Ferrous Metals do not contain Iron, are not magnetic and are usually more resistant to corrosion than ferrous metals

Ferrous MetalsName Properties Typical Uses

Cast Iron Hard skin, softer underneath, but brittle, corrodes by rusting but better resistance than steel

Parts with complex shapes which can be made by casting

Ferrous MetalsName Properties Typical Uses

Mild Steel

Tough, ductile, malleable, good tensile strength, poor resistance to corrosion

General structural work for example girders, nuts, bolts, screws, car body panels and non-cutting tools

Ferrous MetalsName Properties Typical Uses

High carbon steel (tool steel)

Even harder than medium carbon steel and more brittle, can be heat-treated to make it harder and tougher

Ferrous MetalsName Properties Typical Uses

Stainless steel

Hard and tough, resistant to wear and corrosion

Non-ferrous Metals

Non-ferrous metals do not contain iron

Non-ferrous MetalsName Properties Typical Uses

Aluminium(pure metal is rarely used) Main alloy is Duralumin

Good strength-to-weight ratio. Strong. Malleable. Good conductor of electricity. Resistant to corrosion. Can be highly reflective. and

Non-ferrous MetalsName Properties Typical UsesCopper Excellent conductor

of heat & electricityMalleableResistant to corrosion

Non-ferrous MetalsName PropertiesBrass (copper + zinc)

Harder and cheaper than copper. Corrosion resistant

Non-ferrous MetalsName Properties Typical UsesBronzeCopper (zinc) + tin

Harder than brass – resistant to salt water corrosion

Non-ferrous MetalsName Properties Typical UsesTin (pure)

Soft, weak, malleable, ductile and resistant to corrosion

Soft solder. Coating steel to form tin-plate

Non-ferrous MetalsName Properties Typical UsesLead (pure)

Soft, weak, malleable, ductile and resistant to corrosion

Alloyed with tin to produce soft solder

Test Yourself

What are metals with iron in them called?

• Ferrous

What are metals that do not have iron in them called?

• Non-ferrous

What are metals that are mixed with other metals called?

• Alloys

What are pure metals called?

• Pure!

What metal would be used?

Cast Iron

What metals could be used?

• Cast Iron and Aluminium alloy

What metal could be used?

• Copper

Bronze is an alloy of what 2 sometimes 3 metals?

• Copper, Tin and sometimes Zinc

What is Bronze used for and why?

• Resistant to salt water – and it’s very hard

What metal is used and why?

• Mild steel – cheap, readily available, malleable, tough.

What metal is this and what properties does it have?

• Hard and tough, resistant to wear and corrosion

What is it? What metal is it made from? What main property does it have? What needs to be done for it to be less brittle?

• Dot / centre punch. High carbon steel. V. Hard needs to be heat-treated to make it less brittle

What metal would these be made from and why?

• Light weight but strong. Malleable and corrosion resistant in the case of the can

What metal would be used and why? What other uses?

• Brass – excellent conductor of electricity. Taps, brass instruments, (brass) screws

What metal would these mild steel cans be coated in and why

• Tin – corrosion resistant

What else is tin used for?

• Alloyed with lead to make solder