Materials Flashcards
Materials are split into…
Groups or classifications
What are the classifications?
- Metal
- Woods
- Polymers
- Papers and boards
- Composites
- Smart materials
- Modern materials
What are the types of classification associated with Metals?
- Ferrous
- Non-Ferrous
- Alloy
What is meant by Ferrous?
A metal which contains mostly iron and carbon. they are magnetic and will rust
What are some examples of ferrous?
Low carbon steel, medium carbon steel iron cast
What is meant by non-ferrous?
A metal that does not contain iron. they are not magnetic and do not rust
What are some examples of non-ferrous metals?
Aluminium, copper, zinc, silver, gold, titanium, tin
What is meant by Alloy?
A metal made of two or more metals or combining two or more elements, one of which must be a metal.
alloys can also be sub-classified as ferrous alloys or non-ferrous alloys
What are some examples of ferrous alloys?
stainless steel and die steel (tool steel)
What are some examples of non-ferrous alloys?
bronze, brass, duralumin, pewter
Metals occurs naturally in the form of…
Ore
What percentage of the Earths crust is metal ore?
Approximately 25%
What are the two most common metal ores?
Bauxite followed by iron
How is the raw metal extracted from the ore?
Through a combination of crushing, smelting or heating, with the addition of chemicals and huge amounts of electrical energy.
most metals can be…
recycled, saving natural resources and limiting the amount of materials imported from abroad
what are the ores for these metals?
- Copper
- Aluminium
- Tin
- Zinc
- Chalcopyrite
- Bauxite
- Cassiterite
- Zinc blende
What metals are non-ferrous?
- aluminium
- copper
- zinc
- silver
- gold
- titanium
- tin
Non-Ferrous metals:
Properties of Aluminium
- Lightweight
- ductile
- malleable
- corrosion-resistant
- electrical and thermal conductor
- can be metal inert gas (MIG) and tungsten inert gas (TIG) heat welded
- melting temp: 660°C
Non-Ferrous metals:
Uses of Aluminium
- Drink cans
- aircraft bodies
- bike frames
- window frames
- packing
- baking foil
Non-Ferrous metals:
Properties of copper
- ductile
- malleable
- tough
- corrosion-resistant
- good electrical and thermal conductor
- can be soldered and brazed
- melting temp: 1083°C
Non-Ferrous metals:
uses of copper
- electrical wire
- printed electrical circuits
- water pipes
- hot water tanks
- central heating pipes
Non-Ferrous metals:
properties of Zinc
- low melting point
- good corrosion resistance
- melting temp: 420°C
Non-Ferrous metals:
uses of zinc
- galvanising steel as a protective coating for dustbins
- dustbins
- farm gates
- intricate die casting
Non-Ferrous metals:
properties of tin
- ductile
- malleable
- low melting point
- corrosion-resistant
- melting temp: 232°C
Non-Ferrous metals:
uses of tin
- soft solder
- coatings for food cans
- rarely used in pure form
What are examples of ferrous metals?
- low-carbon steel
- medium carbon steel
- cast iron
- mild steel
Ferrous metals:
properties of Low carbon steel
- ductile
- high tensile strength
- tough
- malleable
- poor resistance to corrosion
- 0.15-0.30% carbon content
- melting temp: 1427°C
Ferrous metals:
uses of low carbon steel
- nuts
- bolts
- washers
- screws
- car bodies
- outer panels for white goods
Ferrous metals:
properties of medium carbon steel
- harder than low carbon steel
- less ductile then low carbon steel
- malleable
- tough
- 0.30-0.70% carbon content
Ferrous metals:
uses of medium carbon steel
- springs
- gardening tools (trowels, forks)
Ferrous metals:
properties of cast iron
- hard outer skin but brittle core
- good under compression
- 3.5% carbon
- melting temp: 1149°C
Ferrous metals:
uses of cast iron
- disk brakes
- machine parts
- engine blocks
- sheet furniture (ie decorative bollards, bins and lighting)
Ferrous metals:
properties of mild steel
- strong
- malleable
- 0.4% carbon
- high tensile strength
- high impact strength
- melting temp: 1410°
Ferrous metals:
uses of mild steel
- construction
what are examples of ferrous alloys?
- stainless steel
- high speed steel (HSS)
- die steel (tool steel)
Ferrous Alloys:
properties of stainless steel
- tough
- hard
- corrosion-resistant
- 10% chrome
- 8% nickel
- melting temp: 1510°C
Ferrous alloys:
uses of stainless steel
- sinks
- kitchenware
- cutlery
What are examples of non-ferrous alloys?
- brass
- bronze
- duralumin
Non-Ferrous alloys:
properties of brass
- corrosion-resistant
- good electrical conductor
- good thermal conductor
- low melting point
- casts well
- 65% copper
- 35% Zinc
- melting temp: 930°C
Non-Ferrous alloys:
uses of brass
- boats fittings
- door furniture
- cast valves and taps
- ornaments
Non-Ferrous alloys:
properties of Duralumin
- equivelant strength and properties to low carbon steel but more lightweight
- ductile
- becomes harder as it is worked
- 4% copper
- 1% magnesium and manganese
Non-Ferrous alloys:
Uses of the Duralumin
- Air crafts
- Vehicle parts
metal stock forms:
sheets are…
large flat sections of metal in varying thicknesses from less than 1mm up yo approximately 3mm
metal stock forms:
plates are…
generally thicker than 3mm and narrower than sheet metals
metal stock forms:
bars are…
solid form, flat bar, square bar, round bar or hexagonal bar
metal stock forms:
tubes are…
hollow in cross-section and can be square, rectangular (also called box section), round or hexagonal
metal stock forms:
structural is…
angular shapes such as H beams, L beams (angle), i beams, tee beams and channel
what are the 3 types of wood?
- Hardwood
- Softwood
- Manufactured board
what are examples of hardwoods?
- oak
- jelutong
- mahogany
- balsa
- beech
What is meant by hardwood?
- a wood from broad-leafed (deciduous) trees
- generally slow-growing
- lose leaves in autumn
Hardwoods:
Properties of Oak
- Hard
- tough
- attractive grain
- good weather resistance
- contains tannic acid which corrodes steel screws or fixings
Hardwoods:
Uses of Oak
- floorings
- furniture
- boat building
- cladding
- interior and exterior joinery
Hardwoods:
Properties of Mahogany
- can contain an interlocking grain (makes it more difficult to work with)
- rich dark red colour
Hardwoods:
Uses of mahogany
- indoor furniture
- shop fittings and cabinets
- veneers commonly used on manufactured boards
Hardwoods:
Properties of beech
- tough
- close-grained
- hard
- available in steamed (white colour) and un-steamed (pink tinge)
- does not impart a taste to food
Hardwoods:
Uses of beech
- chairs
- chopping boards
- tools (mallets)
- steam-bent laminated furniture
- turned bowls
Hardwoods:
Properties of jelutong
- low density
- straight grain
- fine texture
- rated non-durable to perishable
- diffuse-porous
- sour odour
- can cause skin irritation
Hardwoods:
Uses of jelutong
- patternmaking
- carving
Hardwoods:
Properties of balsa
- pale reddish-brown
- most boards of balsa are made from sapwood which is white to off-white or tan, sometimes with a pink or yellow hue
- straight grain
- perishable
- susceptible to insect attack
*
Hardwoods:
uses of balsa
- buoys
- rafts
- surfboards
- model aeroplanes
- musical instruments
- packing/transport cases
- core stock in sandwich laminations
- fishing lures
*
What is meant by softwood?
- a wood from coniferous (cone-bearing) trees
- fast growing
- tend to be evergreen
what are examples of softwood?
- pine
- redwood
- cedar
- larch
Softwoods:
Properties of pine
- straight grain
- knotty
- can contain resinous knots
Softwoods:
Uses of pine
- construction work
- roof beams
- timber frame construction
- interior joinery
Softwoods:
Properties of Cedar
- straight grain
- can corrode ferrous metals due to acidic nature
- low density
- good sound damping
- good resistance to moisture
Softwoods:
uses of cedar
- exterior cladding
- sheds
- greenhouses
- beehives
- interior panelling
Softwoods:
Properties of Larch
- Hard
- tough
- attractive grain pattern fades to silver upon exposure
- good resistance to moisture