Metals

Using these general rules will help you answer most questions relating to Ferrous Metals:

• As carbon content is increased, ferrous metals become more brittle and harder
• Ferrous metals contain iron which makes them magnetic
• Ferrous metals are prone to rust and corrosion due to the iron within the metals
• Ferrous metals tend to be used in construction and as tools due to their good mechanical properties

Mild Steel (0.05% - 0.30% carbon content):

Advantages	Disadvantages
Versatile material Easily worked Malleable Ductile Good tensile strength	Mild steel contains iron and so it rusts easily Limited ways to be treated (only case hardening) Poor strength to weight ratio

Uses: General engineering, Construction, Nuts and Bolts, Pipelines, Machinery parts

Medium Carbon Steel (0.30% - 0.60% carbon content):

Advantages	Disadvantages
Harder than mild steel Ductile Strong material Wear resistant	Due to increased carbon content it is less ductile/malleable than mild steel Hard to shape/cut

Uses: Garden tools, Springs, Gears, Railroad

High Carbon Steel (0.60% - 1.0% carbon content):

Advantages	Disadvantages
Extremely hard/strong Cheap in comparison to other hard materials	Brittle due to high carbon content Expensive Difficult to form/cut/weld

Uses: Drills, Expensive, Knives

Cast Iron (2.0% - 4.0% carbon content):

Advantages	Disadvantages
Good casting properties High machinability Good wear resistance Corrosion resistant	Very heavy Brittle Low tensile strength

Uses: Machinery, Cooking pots, Disk brakes, Pipes

Using these general rules will help you answer most questions relating to Non-ferrous Metals:

• Non-ferrous metals are more corrosion resistant than ferrous metals
• Non-ferrous metals tend to be more expensive than ferrous metals due to their rarity
• Non-ferrous metals tend to be lighter than ferrous metals

Aluminium:

Advantages	Disadvantages
Lightweight Corrosion resistant Good conductor of electricity Malleable	Cracks under stress Needs annealing when worked Does not withstand great loads

Uses: Aircraft, Engine parts, Utensils, Tins

Copper:

Advantages	Disadvantages
Good heat and electrical conductor Ductile Malleable Soft	Needs annealing when worked Danger of electrolysis when in contact with water Corrodes easily Expensive

Uses: Electrical cables, Circuits, Generators, Heating

Zinc:

Advantages	Disadvantages
Corrosion resistant Self-healing Recyclable Durable	Low toughness Brittle when worked May corrode when in contact with water/moisture for a long time

Uses: Roofing, Castings, Batteries

Tin:

Advantages	Disadvantages
Malleable Ductile Corrosion resistant	Hard to recycle Not very strong

Uses: Furniture, Construction, Exterior furniture, Veneers

Stainless Steel (Chromium, Nickel, Steel):

Advantages	Disadvantages
Corrosion resistant Heat resistant Can be recycled Good strength to weight ratio Hygenic/non-toxic	Expensive Hard to machine

Uses: Kitchen utensils, Medical tools, Construction

Duralumin (Aluminium, Copper, Manganese):

Advantages	Disadvantages
Lightweight Strong Casts well Tough/hard	Not corrosion resistant Brittle

Uses: Aviation industry, Automobile industry, Pipelines

Brass (Copper, Zinc):

Advantages	Disadvantages
Casts well Easy to machine Good conductor of heat and electricity Low friction coefficent	Susceptible to cracking when cold worked Needs to be constantly annealed Not very corrosion resistant

Uses: Ship propellers, Electrical components, Locks, Gears

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