METALS

Ferrous metals

• contain iron

• prone to rusting

What are ferrous metals?

• Cast iron

• Stainless steel (alloy)

• High speed steel

• Mild steel

• High carbon steel

What are the non ferrous metals?

• Lead

• Tin

• Zinc

• Aluminium

• Copper

Cast iron

• high melting point

• Brittle

• Used in car break disks

Stainless steel

• Hard

• wear resistant

• Used in cutlery, kitchen equipment

High speed steel

• alloy with chronium

• brittle and wear resistant

• Drill bits, lather tools

Mild steel

• Tough

• Ductile

• malleable

• Used in nuts, bolts, engineering

High carbon steel

• Hard and tough

• Used in cutting tools, screwdrivers, chisels and saws

Lead

• soft and malleable

• used in roofing, construction, casting

Tin

• ductile

• malleable

• tin foil, cans

Zinc

• coating on screws, nails to galvanise steel

Aluminium

• electrical conductivity

• corrosion resistant

Copper

• electrical conductor

• malleable

• electrical cables

Alloys

mixture of two or more metals to give desired propertiess

Duralumiunium

• aluminium and copper

• aircraft, boats and cars

Brass

• copper and zinc

• decorative work

Bronze

• acrtistic and sculptural pices

Work hardening

process of increasing hardness of steel, causes it to be very brittle

Tempering

reheating after hardening to reduce brittleness

Annealling

• Heating metal and allowing it too cool slowly

• Makes it easier to work with and increases ductility

Case hardening

• Carbon added to surface of steel

• increases hardness outside, leaves flexible core