7 - Performance characteristics of metals Flashcards
What are metals? (5)
- Are a naturally occurring material
- mined from the ground
- Approx. 25% of earth’s crust is made up of metal ores
- Bauxite is the most common
- Metals is extracted through a combination of crushing, smelting and heating with addition of chemicals and huge amounts of electrical energy
What ore does copper come from
Chalcopyrite
What ore does aluminium come from
Bauxite
What ore does tin come from
Cassiterite
What ore does zinc come from
Zinc blende
What are non ferrous metals
Are metals which don’t contain iron
What are ferrous metals (2)
- Are metals containing mostly iron and carbon
- Are magnetic and will rust
What are alloys
A metals made for two or more metals, or combing two or more elements, one of which must be a metal
Example of non ferrous metals (7)
• Aluminium • Copper • Zinc • Silver • Gold • Titanium • Tin
Examples of ferrous metals (3)
• Low carbon steel • Medium carbon steel • Cast iron
Examples of ferrous alloys
• Stainless steel • High speed steel (HSS) • Die steel (tool steel)
Example of non-ferrous alloys (4)
• Bronze • Brass • Duralumin • Pewter
Properties of aluminium (7)
- Lightweight
- Ductile
- Malleable
- Corrosion resistant
- Electrical and thermal conductor
- Can be (MIG) and (TIG) heat welded
- Melting temp 660°C
Uses of aluminium (6)
- Drink cans
- Aircraft bodies
- Bike frames
- Window frames
- Packaging
- Baking foil
Uses of copper (5)
- Electrical wire
- Printed Electrical circuits
- Water pipes
- Hot water tanks
- Central heating pipes
Properties of copper (7)
- Ductile
- Malleable
- Tough
- Corrosion resistant
- Good Electrical and thermal conductor
- Can be soldered and brazed • Melting temp 1083°C
Properties of zinc (3)
- Low melting point
- Good Corrosion resistance
- Melting temp 420°C
Uses of Zinc (4)
- Galvanising steel as protective coating for dustbins
- Buckets
- Farm gates
- Intricate die castings
Properties of silver (5)
- Malleable
- Ductile
- Corrosion resistant
- Can be soldered
- Melting temp 962°C
Uses of silver (3)
- Jewellery
- Cutlery
- Used for plating other materials
Properties of gold (5)
- Malleable
- Ductile
- Corrosion resistant
- Can be soldered
- Melting temp 1063°C
Uses of Gold (4)
- Jewellery
- Electronic components
- Connectors
- Switch components
Properties of titanium (4)
- Hard
- Similar strength to steels but more lightweight
- High resistance to Corrosion
- Melting temp 1668°C
Uses of titanium (8)
- Joint replacements
- Tooth implants
- Spectacle frames
- Aircraft
- Spacecraft
- Golf clubs
- Bicycles
- Ship hulls
Properties of tin (5)
- Ductile
- Malleable
- Low Melting point
- Corrosion resistant
- Melting temp 232°C
Uses of tin (3)
- Soft solder
- Coatings for food cans
- Rarely used in pure form
Properties of low carbon steel (7)
- Ductile
- High tensile strength
- Tough
- Malleable
- Poor resistance to Corrosion
- 0.15-0.30% carbon content
- Melting temp 1427°C
Uses of low carbon steel (6)
- Nuts
- Bolts
- Washers
- Screws
- Car bodies
- Outer panels for white goods
Properties of medium carbon steel (3)
- Harder than low carbon steel but less Ductile
- Malleable and Tough
- 0.30-0.70% carbon content
Uses of medium carbon steel (2)
- Springs
- Gardening tools (trowels, forks)
Properties of cast iron (4)
- Hard outer skin but brittle core
- Good under compression
- 3.5% carbon
- Melting temp 1149°C
Uses of cast iron (6)
- Disc brakes
- Machine parts
- Engine blocks
- Sheet Furniture e.g decorative bollards
- Bins
- Lighting
Properties of stainless steel (5)
- Tough
- Hard
- Corrosion resistant
- 18% chrome, 8% nickel
- Melting temp 1510°C
Uses of stainless steel (3)
- Sinks
- Kitchenware
- Cutlery
Properties of high speed steel (HSS) (4)
- Hard
- Tough
- High level of resistance to frictional heat
- 18% tungsten 4% chromium 1% vanadium 0.5-0.8% carbon
Uses of high speed steel (HSS) (4)
- Tool blades
- Drill bits
- Milling cutters
- Router bits
Properties of die steel (tool steel) (2)
- Hard
- Tough
Uses of die steel (tool steel) (3)
- Blanking pushes and dies
- Extruder dies
- Fine press tools
Properties of bronze (5)
- Tough
- Corrosion resistant
- Can be cast
- 90% copper 10% tin
- Melting temp 850-1000°C
Uses of bronze (3)
- Statues
- Coins
- Bearings
Properties of brass (6)
- Corrosion resistant
- Good Electrical and thermal conductor
- Low melting point
- Casts well
- 65% copper 35% zinc
- Melting temp 930°C
Uses of brass (4)
- Boats fittings
- Door Furniture
- Cast valves and taps
- Ornaments
Properties of duralumin (4)
- Equivalent strength properties to low carbon steel but more lightweight
- Ductile
- Becomes harder as it’s worked
- 4% copper 1% magnesium and manganese
Uses of duralumin (2)
- Aircraft parts
- Vehicle parts
Properties of pewter (5)
- Malleable
- Low melting point
- Casts well
- 85-99% tin, with remainder consisting of copper and antimony
- Melting temp 170-230°C
Uses of pewter (7)
- Tankards
- Flasks
- Goblets
- Photo frames
- Decorative items
- Candlesticks
- Sports trophies
Metal stock forms (5)
- Sheet - large flat sections of metal in varying thicknesses from less than 1mm up to approximately 3mm
- Plate - is generally thicker than 3mm and narrower than sheet metals
- Bar - is solid form, flat bar, square bar, round bar or heaxagonal bar
- Tube - is hollow in cross-section and can be quads, rectangular round or hexagonal
- Structural angular - shapes such as H beams, L beams, I beams, tee bar and channel
How is aluminium suitable for Aircraft bodies? (3)
- Aluminium is lightweight and strong
- Aluminium doesn’t corrode as readily compared to steels
- Aluminium holds its strength at higher temperatures
How is aluminium suitable for bike frames? (3)
- corrosion resistant asking it last longer
- Fairly lightweight
- High strength-to-weight ration
How is aluminium suitable for window frames? (2)
- Robust especially when exposed to the elements
- Unaffected by UV rays
How is aluminium suitable for packaging and foil?
Provides a complete barrier to light, oxygen, moisture and bacteria
How is aluminium suitable for drink cans? (5)
- Malleable which allows the can to be deep drawn into shape
- Lightweight which makes it easy to lift and transport
- A food shape material, user won’t be poisoned when drinking from the can
- Doesn’t rust in contact with the liquid
- Easily recyclable due to low melting point
