Non-Ferrous Metals

Question 1

What is the source of copper?

Answer 1

• Copper ore
  From low-grade copper sources via:
• phytomining
• bioleaching

Question 2

Properties of copper

Answer 2

• good electrical and thermal conductor
• corrosion resistant; low reactivity
• very ductile and malleable
•Tough
•Polishes well but can oxidise to a green colour
•Welds easily
- easily alloyed with other metals (eg for brasses and bronzes)

Question 3

What is the appearance of copper

Answer 3

Rose colour / red-brown

Question 4

Applications of copper

Answer 4

• Electrical wiring and electromagnets
• Tubing
• Kettles
• Bowls
• Water pipes and plumbing parts
• Roofing (it’s waterproof)

Question 5

Source of aluminium

Answer 5

Bauxite

Question 6

Properties of aluminium

Answer 6

• Low density
• Corrosion-resistant by forming an oxidation layer
• Strong even when under tensile stress
• Good conductor
• Soft, malleable and ductile (so bends and dents easily)
• Machines well and easily worked

Question 7

Appearance of aluminium

Answer 7

• Reflective

- Light grey with matt finish

Question 8

Uses of pure aluminium

Answer 8

• Wide range of domestic products and containers eg kitchen utensils
• packaging eg foil and drink cans
  (because it is strong, light, corrosion resistant and ductile, so easily formed)

Question 9

Potential compositions of aluminium alloys

Answer 9

Up to 97% aluminium

• Up to 5% silicon
• Up to 3% copper
• Up to 0.8% magnesium
• Up to 0.8% manganese

Question 10

Properties of aluminium alloys

Answer 10

Adapted properties of pure aluminium

• May decrease density
• May increase strength
• Good fluidity when molten
• Ductile and malleable

Question 11

Uses of aluminium alloys

Answer 11

• Electrical power lines
• Aircraft parts
• Motor vehicle components
• Light sand and die casting (fluidity)

Question 12

Source of titanium and its alloys

Answer 12

Titanium ore
-> titanium tetrachloride
Uses the Kroll process

Question 13

Properties of titanium and its alloys

Answer 13

• Strong
• Low density
• Corrosion resistant and good biocompatibility (not toxic nor rejected by the body)
• Resistance to rapid pressure changes
• Very elastic

Question 14

Common applications of titanium and its alloys

Answer 14

• Aircraft parts
• Medical hardware and implants, specifically hip joint replacements
• Protection of hulls of ships and things exposed to seawater
• Pigment in house paint

Question 15

Source of zinc metal

Answer 15

Sulfide ores

Question 16

Properties of zinc

Answer 16

• Good fluidity when molten (flows better than aluminium, with less pressure needed for a die cast)
• More reactive than iron/steel. Tarnishes in air
• Hard and brittle but malleable/ductile when heated
• Moderate conductivity
• Weak (<0.5 tensile str of mild steel)

Zinc alloys generally have higher impact strength

Question 17

Appearance of zinc

Answer 17

Silvery-blue with a matt finish

Question 18

Common applications of zinc

Answer 18

• Protective coating (eg sacrificial metal of iron and for galvanising steel)
• Alloy to make brasses

Question 19

Source of tin

Answer 19

River deposits, smelted and refined

Question 20

Properties of tin

Answer 20

• Very soft, malleable and ductile; easy to form
• Highly resistant to corrosion
• Good conductivity

Question 21

Appearance of tin

Answer 21

• Shine and silver colour

Question 22

Common applications of tin

Answer 22

• Alloying to make solder
• Protective coating
• Some food cans

Question 23

Source of tungsten

Answer 23

Wolframite (mineral)

Question 24

Properties of tungsten

Answer 24

• Resistant to acids
• Brittle but ductile at high temperatures
• Highest melting point of all elements
• Very high tensile strength
• Lowest coefficient of thermal expansion
• Tungsten carbide is veyr hard and tough

Question 25

Applications of tungsten

Answer 25

• Old incandescent bulb filaments
• Drill bits and tools
• Used in rocket engines and reentry surfaces

Question 26

Composition of brasses

Answer 26

• Up to 70% copper
• Up to 40% zinc
• Up to 1% tin

Question 27

Properties of brasses

Answer 27

With high zinc contant:
- Very strong and tough
- Fluid when molten
With high copper content:
- Very ductile and malleable

Generally:

• Low friction
• Can be corrosion resistant
• Able to be cast and machined

Question 28

Appearance of brasses

Answer 28

Gold coloured and darkens when oxidised with age

Question 29

Applications of brasses

Answer 29

• Musical instruments (friction) and ornamental hardware
• Forgings and casting for a wide range of engineering and marine components
• -> retain strength
• -> low melting point
• Plumbing applications eg water taps
• Bullet cartridges (friction)