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DT > Section 2 > Flashcards

Section 2 Flashcards

1
Q

Define strength

A

The ability to withstand forces like compression without breaking

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2
Q

Define hardness

A

The ability to withstand scratching, abrasion or denting

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3
Q

Define toughness

A

How hard a material is to break or snap

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4
Q

Define elasticity

A

How well a material can, stretch and bend and then return to its original shape

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5
Q

Define ductility

A

Ductile materials can be drawn into a wire

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6
Q

Define malleablity

A

The ability for materials to be bent or shaped

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7
Q

What are examples of working properties of materials?

A

-Ductility
-Malleability
-Hardness
-Toughness
-Strength
-Elasticity

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8
Q

What are some examples of physical properties in materials?

A

-Electrical conductivity
-Thermal conductivity
-Fusability
-Density
-Absorbency

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9
Q

Define electrical conductivity

A

Electrical conductors allow electricity to travel through them

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10
Q

What are some examples of materials with good electrical conductivity?

A

-Electrical wires
-Metals
-Fabrics can be coated/blended with metal

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11
Q

What are examples of insulators?

A

Plastics

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12
Q

Define thermal conductivity

A

Thermal conductors let heat travel through them easily

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13
Q

Define an electrical insulator

A

A material that doesn’t let electricity travel through it

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14
Q

Define a thermal insulator

A

A material that doesn’t let heat travel through it

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15
Q

What are examples of thermal conductors?

A

-Metals
-Pans (metal)

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16
Q

What are some examples of thermal insulators?

A

-Plastic
-Board
-Wood

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17
Q

Define fusability

A

Materials with a high fusibility have a low melting point

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18
Q

What is an example of a material with a high fusibility?

A

Solder

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19
Q

Define density

A

The density of a material is a measure of its mass per unit volume

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20
Q

Define absorbency

A

Materials that are absorbent are good at soaking up moisture

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21
Q

What is an example of an absorbent material?

A

Paper towels
Natural fibres (wool and cotton)

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22
Q

What are properties of absorbent materials?

A

-Dyed easily
-Vulnerable to stains
-Dry slower

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23
Q

What is an example of a material that is non absorbent?

A

Synthetic fibres like polyester

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24
Q

What are the properties of non metals compared to metals?

A

-More brittle
-Not always solid at room temperature
-Poor electrical conductors
-Dull looking
-Less dense

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25
Q

What are the properties of metals compared to non metals?

A

-Strong
-Malleable
-Good conductors of heat and electricity
-Not fusible
-Have high melting and boiling points

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26
Q

What is an alloy?

A

A mixture of two or more metals or a mixed metal with one of more elements

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27
Q

What are the different types of paper?

A

-Cartridge
-Layout
-Tracing
-Grid
-Bleed proof

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28
Q

What are the properties of cartridge paper?

A

-High quality
-Textured surface
-Good for sketching with different drawing materials like pencils, crayons and inks

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29
Q

What are the properties of layout paper?

A

-Thin
-Translucent
-Used for general design work and sketching ideas

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30
Q

What are the properties of tracing paper?

A

-Semi transparent
-Used for copying images

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31
Q

What are the properties of grid paper?

A

-May have a square of isometric pattern
-Used for orthographic and scale drawings
-Isometric paper is used for isometric drawings

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32
Q

What are the properties of bleed proof paper?

A

-The ink doesn’t spread out/bleed
-Used when drawing with felt tips and marker pens

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33
Q

What is a paper above 200gsm (weight)?

A

A board

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34
Q

What are the types of board?

A

-Solid white
-Ink jet card
-Corrugated card
-Duplex card
-Foam core board
-Foil lined board

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35
Q

What are the properties of solid white board?

A

-High quality bleached surface
-Ideal for printing
-Used for primary packaging

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36
Q

What are the properties of ink jet card?

A

-Used for ink jet printing
-The ink doesn’t bleed
-Allows for a sharply defined and high quality image

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37
Q

What are the properties of corrugated card?

A

-Made up of a fluted inner core sandwiched between two layers
-The liner can be printed on
-The flutes add strength and rigidity
-Used in secondary packaging to protect products

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38
Q

What are the properties of duplex board?

A

-Has a different colour and texture on each side
-Only one surface can be seen which is smooth as it is used for printing
-Used for food packaging

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39
Q

What are the properties of foam core board?

A

-Made by sandwiching expanded polystyrene foam between 2 layers of card
-It is stiff and lightweight
-Used for making models and posters
-The outer layer can be scored

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40
Q

What are the properties of foil lined board?

A

-Lined with aluminium foil
-Used for package food
-Keeps the flavours in and air and moisture out

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41
Q

Where and how do softwoods grow?

A

-Colder climates
-Fast growing

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42
Q

Why are softwoods cheap and readily accesible?

A

As they are fast growing

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43
Q

What are examples of softwoods?

A

-Larch
-Spruce
-Pine

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44
Q

What are the properties of pine?

A

-Yellow with brown streaks
-Strong and cheap
-Knotty - makes it harder to work with
-Used for fences and cheap furniture

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45
Q

What are the properties of larch?

A

-Attractive yellow to reddish colour
-Harder, tougher and stronger than most softwoods
-Rot resistant
-Used for decking, cladding and fence posts

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46
Q

What are the properties of spruce?

A

-Reddish brown colour
-Hard and good strength to weight ratio
-Knotty and not very durable
-Used for aircraft, ship masts and crates

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47
Q

Where and how do hardwoods grow?

A

-Warm climates
-Slow growing

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48
Q

Why are hardwoods expensive?

A

As they are slow growing

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49
Q

What happens when ink bleeds?

A

It spreads out

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50
Q

What is the difference between a paper and a board?

A

Boards are above 200gsm whereas papers are below 200gsm

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51
Q

What are some examples of hardwoods?

A

-Oak
-Mahogany
-Beech
-Balsa
-Ash

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52
Q

What are the properties of oak?

A

-Light brown
-Tough, durable and strong
-Attractive grain
-Used for flooring and furniture
-It does corrode steel screws and fittings

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53
Q

What are the properties of mahogany?

A

-Red brown colour
-Durable and easy to work with
-Expensive
-Used for expensive furntiure

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54
Q

What are the properties of beech?

A

-Pinkish brown
-Hard enough to resist dents
-Can be bent using steam
-Doesn’t splinter
-Used in children’s toys and chairs

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55
Q

What are the properties of balsa?

A

-White or tan colour
-Low density for a hardwood
-Very soft
-Easy to cut and shape
-Great for modelling
-High strength to weight ratio

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56
Q

What are the properties of ash?

A

-Pale cream colour
-Tough and absorbs shock well
-Used for tool handles and sports equipment
-Attractive - used in furniture

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57
Q

What are ferrous metals?

A

Metals that contain iron

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58
Q

What are examples of ferrous metals?

A

-Cast iron
-Low carbon steel
-High carbon steel

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59
Q

What are the properties and uses of cast iron?

A

-very strong if compressed
-Brittle and not malleable
-Used for bench vises and car brake disks

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60
Q

What are the properties and uses of low carbon steel?

A

-Quite strong and cheap
-Rusts easily
-Can’t be hardened
-Used for car bodies, screws and nuts and bolts

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61
Q

What are the properties and uses of high carbon steel?

A

-Harder than low carbon steel
-Can be hardened
-Not easy to work with
-Rusts
-Used for Tools, chisels, files and drills

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62
Q

How can you prevent a ferrous metal from rusting?

A

Adding a protective coating like paint

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63
Q

What are non ferrous metals?

A

Metals that don’t contain iron

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64
Q

What are examples of non ferrous metals?

A

-Aluminium
-Brass
-Copper
-Tin
-Zinc

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65
Q

What are the properties and uses of aluminium?

A

-Lightweight and corrosion resistant
-Expensive and not as strong as steel
-Hard to join
-Used for aeroplanes, cans and ladders

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66
Q

What are the properties and uses of brass?

A

-Quite strong
-Corrosion resistant
-Malleable
-Ductile
-Used for electrical parts, door handles and taps

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67
Q

What are the properties and uses of copper?

A

-Relatively soft
-Malleable
-Ductile
-Very good electrical conductor
-Used for pipes and electrical wiring

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68
Q

What are the properties and uses of tin?

A

-Soft
-Corrosion resistant
-Malleable
-Ductile
-Low melting point
-Used for tin cans, foil and alloying metal in solder

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69
Q

What are the properties of zinc?

A

-Not very strong
-Corrosion resistant
-Used for coating steel, buckets and watering cans

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70
Q

What are the properties of the alloy high speed steel?

A

-Keeps hardness when heated to high temperatures
-Used in high speed cutting tools

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71
Q

What are the properties and uses of brass (Copper and zinc)?

A

-Harder and stronger than both copper and zinc
-Malleable
-Ductile
-Good electrical conductor
-Resistant to corrosion

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72
Q

What are the properties and uses of stainless steel (iron and carbon and chronium and nickel)?

A

-High strength, toughness, ductility
-More rust resistant than low and high carbon steel
-Used for surgical equipment, sinks and cutlery

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73
Q

What are the 2 types of plastics?

A

-Thermoforming
-Thermosetting

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74
Q

What is a thermoforming polymer?

A

-Plastics that have a low heat resistance
-Easily formed into different shapes by heating, melting and remoulding
-Easy to recycle

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75
Q

What are examples of thermoforming polymers?

A

-Acrylic (PMMA)
-High density polyethylene (HDPE)
-Polyethylene terephtalate (PET)
-High impact polystyrene (HIPS)
-Polyvinyl chloride (PVC)
-Polypropylene (PP)

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76
Q

What are the properties of acrylic (PMMA)?

A

-Hard
-Stiff
-Shiny
-Resists weather well
-Used for motorcycle helmet visors and signs
-Quite brittle

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77
Q

What are the properties of high density polyethylene (HDPE)?

A

-Stif
-Strong
-Lightweight
-Used for washing up bowls and folding chairs

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78
Q

What are the properties of polyethylene terephtalate (PET)?

A

-Light
-Strong
-Tough
-Used to make see through drink bottles and fibres for clothes

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79
Q

What are the properties of high impact polystyrene (HIPS)?

A

-Rigid
-Fairly cheap
-Used for boxes like CD cases and smoke detector casings

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80
Q

What are the properties of polyvinyl chloride (PVC)?

A

-Quite brittle
-Cheap
-Durable
-Used for blister packs and window frames

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81
Q

What are the properties of polypropylene (PP)?

A

-Quite tough and flexible
-Can be made in a variety of bright colours
-Used for plastic chairs
-Confortable

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82
Q

What are thermosetting plastics?

A

-Plastics that resist heat and fire
-They undergo a chemical change when heated and moulded
-Once moulded they’re permanently hard and rigid
-Difficult to recycle

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83
Q

What are examples of thermosetting plastics?

A

-Epoxy resin
-Urea formaldehyde (UF)
-Melamine formaldehyde (MF)
-Phenol formaldehyde (PF)
-Polyester resin (PR)

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84
Q

What are the properties of epoxy resin (ER)?

A

-Rigid
-Durable
-Corrosion resistant
-Good electrical insulator
-Used for circuit boards and wind turbine rotor blades

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85
Q

What are the properties of Urea formaldehyde(UF)?

A

-Hard
-Brittle
-Good electrical insulator
-Used for plug sockets and cupboard handles

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86
Q

What are the properties of melamine formaldehyde(MF)?

A

-Strong and scratch resistant
-Used to laminate chipboard and for plates and bowls

87
Q

What are the properties of polyester resin(PR)?

A

-Hard
-Stiff
-Cheap
-Good electrical insulator
-Waterproof
-Used for kayaks, shower stalls and garden furniture

88
Q

What are the properties of Phenol formaldehyde?

A

-Hard and heat resistant
-Easily moulded
-Used in bottle caps and snooker balls

89
Q

What are natural fibres?

A

Fabrics that can be harvested from plants and animals

90
Q

What are the properties of natural fibres?

A

-Biodegradable
-Recyclable
-Renewable
-Absorbent
-Strong when dry
-Poor resistance to biological damage

91
Q

What are the positives and negatives of cotton?

A

-Positives
-Strong and hard wearing
-Comfortable to wear
-Add colour to
-Easy to wash

-Negatives
-Creases easily
-High flammability
-Poor elasticity
-Can shrink when washed
-Dries slowly

92
Q

What are the uses of cotton?

A

-Jeans
-T-shirts
–Soft furnishings
-Blouses

93
Q

What are the positives and negatives of wool?

A

-Positives
-Warm
-Absorbent
-Good elasticity
-Low flammability
-Crease resistant

-Negatives
-Can shrink when washed
-Fairly expensive
-Can feel itchy
-Dries slowly

94
Q

What are the uses of wool?

A

-Suits
-Jumpers
-Coats
-Dresses
-Carpets

95
Q

What are the positives and negatives of silk?

A

-Positives
-Smooth
-Resistant to shrinking
-Absorbent
-Low flammability
-Sun resistant

-Negatives
-Creases easily
-Might not wash well
-Expesnive
-Weak when wet

96
Q

What are the uses of silk?

A

-Lingerie
-Underwear
-Dresses
-Shirts
-Ties

97
Q

What are synthetic fibres?

A

-Fibres made from polymers

98
Q

What are the properties of synthetic fibres?

A

-Non renewable
-Resistant to biological change
-Can be changed by heating
-Not very absorbent
-Hard to dye

99
Q

What are examples of natural fibres?

A

-Wool
-Cotton
-Silk

100
Q

What are examples of synthetic fibres?

A

-Elastane
-Polyester
-Polyamide

101
Q

What are the positives and negatives of elastane?

A

-Positives
-Extremely elastic
-Strong
-Hard wearing
-Lightweight

-Negatives
-Not absorbent
-High flammability
-Not biodegradable

102
Q

What are synthetic fibres made from?

A

-Coal and oil

103
Q

What are natural fibres made from?

A

Plants and animals

104
Q

What are the uses of elastane?

A

-Sportswear
-Underwear

105
Q

What are the positives and negatives of polyester?

A

-Positives
-Strong even when wet
-Low flammability
-Good elasticity
-cheap
-Resists creasing

-Negatives
-Not absorbent
-Not biodegradable
-Damaged by strong acids

106
Q

What are the uses of polyester?

A

-Sportswear
-Bed sheets
-Curtains
-Cushions

107
Q

What are the positives and negatives of polyamide?

A

-Positives
-Strong and hard wearing
-Warm
-Crease resistant
-Fairly cheap

-Negatives
-Not very absorbent
-Damaged by sunlight
-Melts as it burns

108
Q

What are the uses of polyamide?

A

-Sportswear
-Socks
-Tights
-Carpets

109
Q

How are fabrics made?

A

Fibres that are spun into yarns

110
Q

What are the 2 types of yarn?

A

-Staple fibres (short lengths)
-Filaments (longer lenghts)

111
Q

What are the properties of filament yarn?

A

-Smooth

112
Q

What are the properties of staple fibre yarn?

A

-Hairier

113
Q

What are the 3 ways of turning fibres into frabrics?

A

-Woven
-Knitted
-Non woven

114
Q

How are woven fabrics made?

A

Interlacing two sets of yarns

115
Q

How are knitted fabrics made?

A

-By interlocking one or more yarns using loops
-The loops trap air so they insulate
-The stretch more than woven fabrics

116
Q

How are non woven fabrics made?

A

-Held together by bonding or felting
-They don’t fray and can be cut in any direction
-Little waste

117
Q

What is the weft?

A

Woven fabric that goes from right to left

118
Q

What is the warp?

A

The woven fabric that goes up and down

119
Q

What are the advantages and uses of a lain weave woven fabric?

A

-Hard wearing
-Strong and holds its shape well
-Smooth finish
-Cheapest weave to produce
-Used to make cotton based fabrics

120
Q

What are the advantages and uses of weaving fabrics using looms?

A

-Used for shirts, upholstery and trousers
-Industrial looms can produce yarn on a large scale
-Yarn can be mass produced and high speed

121
Q

What are the 2 ways to knit yarns?

A

-Weft
-Warp

122
Q

What are the properties and uses of weft knitted fabrics?

A

-The yarn runs across the fabric making interlocking loops with the row of yearn beneath
-These fabrics stretch and can lose their shape easily
-Can unravel forming a ladder
-The’re used to make jumpers, socks and T-shirts

123
Q

What are the properties and uses of warp knitted fabrics?

A

-The yarn runs up the fabric in loops which interlock vertically
-They’re stretchy but keep their shape
-Hard to unravel
-Made by machine
-Used in swimwear, tights and fleeces

124
Q

What are the 2 ways to make non woven fibres?

A

-Bonded
-Felted

125
Q

What is a bonded fabric?

A

-A web of synthetic fibres that are glued, needle punched, stitched or melted together
-Used in medical masks and artificial leathers

126
Q

What is a felted fabric?

A

-Felt is made by combining pressure, moisture and heat to interlock a mat of wool fibres
-Felt is used to make carpets, jewellery and snooker table coverings

127
Q

What are the 2 ways of combining fabrics?

A

-Blend
-Mix

128
Q

How do you blend fibres?

A

-When two of more different fibres are combined to produce yarn
-This is them woven or knitted to make a blended fabric

129
Q

How to you mix fibres?

A

-When a fabric is made up of two or more different types of yarn
-The two different types of yarn can be knitted or woven together to make a mixed fabric

130
Q

What are examples of manufactured boards?

A

-Medium density fibreboard (MDF)
-Plywood
-Chipboard

131
Q

What are the properties of MDF?

A

-Made from tiny fibres of softwood timber held together by glue
-No natural grain
-Cheap
-Dense
-Porous and can be damaged by moisture
-Used for shelves and flat pack funriture

132
Q

What are the properties of plywood?

A

-Plywood is made up of several layers of softwood of hardwood
-They are glued with their grain at right angles to one another
-Very strong
-Used for building and funiture

133
Q

What are the properties of chipboard?

A

-Chipboard is made by compression wood chips, shavings and sawdust together
-It usually has a veneered surface
-It is cheap
-Not very strong
-Absorbent
-Can be damaged by moisture
-Used for cheap self assembly furniture

134
Q

What three blocks can systems be broken down into?

A

-Input
-Process
-Output

135
Q

What is a system?

A

A collection of parts that work together to do a particular function

136
Q

What is a signal?

A

Something like movement or light that passes from one block to the next

137
Q

What is a printed circuit board (PCB)?

A

Boards with thin copper tracks connecting components in a circuit instead of wires

138
Q

What are the advantages of a PCB?

A

It reduces size and the manufacturing cost of electronic systems

139
Q

Why is copper used for the wire of tracks in a circuit?

A

As it is a good electrical conductor, malleable and ductile

140
Q

What is voltage?

A

-From a power cell or the mains pushes the electric current around a circuit

141
Q

What do resistors do?

A

Can be used to reduce the current in a circuit

142
Q

In a circuit what are examples of input, process and output blocks?

A

Input = switch or button
Process = Timer
Output = Buzzer, lamp

143
Q

What are the 3 types of switches?

A

-Toggle
-Push
-Slide

144
Q

What is the function of variable resistors?

A

-Change the resistance of the circuit based on an external factor
-This alters the current

145
Q

What are the 3 types of variable resistor?

A

-Thermistors
-Pressure sensors
-Light dependent resistors

146
Q

What external factor do thermistors detect and what are the uses?

A

-Detect temperature
-In hot conditions -resistance falls
-Used in central heating

147
Q

What external factors do light dependent resistors detect and what are the uses?

A

-Light sensors
-Brighter light resistance falls
-Used in automatic night lights

148
Q

What external factors do pressure sensors detect and what are the uses?

A

-Detect pressure in a system
-In cars they’re used to detect if there is a leak in a fuel system
-A leak causes pressure to fall which triggers a warning light

149
Q

What is an integrated circuit (IC)?

A

-They’re tiny self contained circuits which have billions of components built in
-They help simplify electronic systems by reducing the number of separate components that are needed in a circuit

150
Q

What are the advantages of using systems with ICs (Integrated circuits)?

A

-They’re cheaper
-They’re smaller
-They use much less power

151
Q

What is a microcontroller?

A

A mini computer on a chip

152
Q

What are the advantages of microcontrollers?

A

-Microcontrollers can do the jobs of multiple ICs so they simplify the system even further
-They can be reprogrammed for different uses

153
Q

What are the disadvantages of microcrontrollers?

A

-They’re more expensive than other ICs

154
Q

What are the ways in which you can program microcontrollers?

A

-By writing a series of commands using programming language
-Creating a flowchart

155
Q

What is the use of a timer in an electronic system?

A

-To add a time delay to a process
-They generate a pulse after a particular length of time has passed

156
Q

What is the use of a counter in an electronic system?

A

-Counters count pulses of voltage produced by an input device

157
Q

What are two uses of timers in electronic circuits?

A

-Controlling flashing lights like car indicators
-The timer in microwaves that time the length of time food cooks for

158
Q

What are uses of counters in an electronic circuit?

A

-A microcontroller counts the number of revolutions that show how fast the engine is turning in a car

159
Q

What are logic gates?

A

They make decisions based on a collection of inputs

160
Q

What are the 3 types of logic gate?

A

-AND
-R
-NOT

161
Q

How does an AND logic gate work?

A

-They have 2 inputs and both need to be on for the output to be on
-For example tumble dryers won’t work unless the start button has been pressed and the door is closed

162
Q

How do OR logic gates work?

A

-They have 2 inputs if one input or the other one is on then the output is on
-For example automatic doors
-The door detects if someone is on the inside of outside

163
Q

How do NOT logic gates work?

A

-They have 1 input
-If that input is on then the output is not on
-For example pressing an emergency stop switch will stop the output

164
Q

What are the 3 examples of output devices and what signal do they produce?

A

-LED - Turns electrcitty into light
-Buzzer - Makes a noise
-Speaker - Turns electrical signals into sound

165
Q

What are the 4 types of motion?

A

-Linear - Moving in a straight line

-Reciprocating - Moving backwards and forwards in a straight line - a piston

Oscillating - Backwards and forwards in an arc - a s wing

Rotary - Moving in a circle - a wheel

166
Q

What is first order lever?

A

-Where the pivot is between the effort and the land
-If the load is closer to the pivot than the effort the lever gives a mechanical advantage which means the effort is smaller
-As you move the pivot closer to load it becomes easier to life

167
Q

What is second order lever?

A

-Where the pivot is at one end of the leaver and the effort is at the other end
-An example of this is a wheelbarrow
-The closer together the pivot and the load are the easier it is to life

168
Q

What is third order lever?

A

-Where the effort is in between the load and the pivot
-An example of this is a fishing rod and tongs
-Moving the effort and pivot further apart makes it easier to move or lift the load

169
Q

What is a linkage?

A

When levers are connected

170
Q

How does a push/pull linkage work?

A

-It used two fixed pivots
-The input and output motions of the linkage are in the same direction.
-The motion of the link arm is in the opposite direction

171
Q

How does a bell crank linkage work?

A

-A bell crank changes the direction of a force by 90 degrees

172
Q

What is a gear?

A

-Toothed wheels that interlock and transfer motion

173
Q

What is a gear train?

A

When two or more gears are linked together and they can be used to change the direction of motion

174
Q

How do you work out gear ratio?

A

Number of teeth on the driven gear/ the number of teeth on the driver gear

175
Q

How do you work out output speed of gears?

A

Speed of driver gear/ gear ratio

176
Q

How do you work out velocity ratio of pulleys?

A

Diameter of the driven pulley wheel/ the diameter of the driver pulley wheel

177
Q

How do you work out output speed of a pulley?

A

Speed of driver pulley wheel/ velocity ratio

178
Q

What are the parts contained in a cam mechanism?

A

-Cam
-Follower

179
Q

What does a circular CAM produce?

A

A uniform reciprocating motion

180
Q

How does a snail CAM work?

A

For half a turn the follower will not move then it will gently rise and then suddenly drop

It only works in one direction

181
Q

How does a pear CAM work?

A

For half a turn the follower will not move then it will gently rise and fall

182
Q

How does a four lobed CAM work?

A

-Has four lobes
-For each turn the CAM follower will rise and suddenly fall four times
-This only works in one direction

183
Q

What is a pulley system made up of?

A

-Wheel
-Cable
-Rope or belt

184
Q

What is the output speed, torque and direction like when the driver pulley and driven pulley are the same size?

A

Direction: Same
Torque: Same
Output speed: Same

185
Q

What is the output speed, torque and direction like when the driver pulley is bigger than the driven pulley?

A

Direction: Same
Output speed: Faster
Torque: Less

186
Q

What is the output speed, torque and direction like when the driver pulley is smaller than the driven pulley?

A

Direction: Same
Output speed: Slower
Torque: Increased

187
Q

What is the output speed, torque and direction like when the driver pulley and driven pulley are the same size when the belt is crossed?

A

Direction: Opposite
Output speed: Same
Torque: Same

188
Q

What are examples where belt drives are used?

A

-Pillar drills
-Washing machines

189
Q

Define the term modern materials

A

Materials that have been developed with a specific application in mind by either inventing new materials or improved manufacturing processes

190
Q

What are examples of modern materials?

A

-Graphene
-Metal foams
-Titanium
-LCDs (Liquid crystal displays)
-Coated metals
-Nanomaterials

191
Q

What are the properties of graphene?

A

-Thin layer of graphite
-Light and strong
-Good conductor of heat and electricity
-Used in tennis rackets, aerospace, vehicles and flexible electronics

192
Q

What are the properties of metal foams?

A

-A metal that contains gas filled spaces
-Lightweight
-Stiff, tough and strong under compression
-Used in bone implants and lightweight car parts

193
Q

What are the properties of titanium?

A

-Extremely corrosion resistant
-High strength to weight ratio
-Used in the aerospace industry
-Developments in CAD/CAM have helped it reduce machining costs and make it more usable
-It can also be used for bikes, ships, armour and dental and bone implants

194
Q

What are the properties of LCDs (liquid crystal displays)?

A

-Used in flat screen displays
-Thin
-Lightweight
-Energy efficient
-Made of a mixture of chemicals and when a current is applied the crystal’s shape changes the image of the screen

195
Q

What are the properties of coated metals?

A

-Iron and steel can be galvanised with zinc to prevent rusting
-Anodised aluminum has a coating of aluminium oxide to make the surface harder and corrosion resistant

196
Q

What are the properties of carbon nanotubes?

A

-Carbon nanotubes - are tiny carbon cylinders with a high strength to weight ratio
-Good conductors
-Used in electronics and can be added to materials to strengthen it without adding much weight

197
Q

What are the properties of self cleaning fabric nanotubes?

A

-They have a nanoparticle coating that remove odors and stains when exposed to light

198
Q

What are the properties of Antibacterial fabrics?

A

-Use nanoparticles of silver to kill bacteria
-Have lots of medical uses like face masks and dressings
-Used in anti bacterial toys and odour free socks

199
Q

Define the term smart material

A

Materials that change their properties in response to stimuli like temperature and light

200
Q

What are examples of smart materials?

A

-Shape memory alloys
-Photochromic inks
-Thermochromic pigments

201
Q

What are the properties of shape memory alloys?

A

-They’re alloys that remember their original shape
-They can be shaped when cool but return to their original shape when heated
-An example is nitinol used in glasses

202
Q

What are the properties of photchromic pigments?

A

-They change colour reversibly in response to light
-They can be put on glasses lenses which turn into sunglasses when it’s sunny

203
Q

What are the properties of thermochromic pigments?

A

-Inks used in colour changing products which react with temperature
-When the temperature changes the product changes colour
-The object returns to its original colour when the temperature returns to its original temperature
-Examples are baby feeding spoons

204
Q

What is a composite material?

A

Composites are made from 2 or more different materials bonded together

205
Q

What are examples of composite materials?

A

-GRP - Glass reinforced plastic
-CRP - Carbonfibre reinforced plastic

206
Q

What are the properties of GRP?

A

-Glass fibres that are coated in a thermosetting plastic resin
-Stronger and tougher than plastic
-Heat resistant and can be easily moulded
-Used in kayaks and boats

207
Q

What are the properties of CRP?

A

-Carbon fibres that are coated in a thermosetting plastic resin
-Lighter than GRP
-Tougher than GRP
-Stronger than GRP
-More expensive than GRP
-Used in protective helmets, sports equipment and bulletproof vests

208
Q

What is a technical textile?

A

-Enhanced fabrics designed to be functional

209
Q

What are examples of technical textiles?

A

-Kevlar
-Nomex
-Micro encapsulation
-Conductive fabrics

210
Q

What are the properties of kevlar?

A

-Synthetic fibre that can be woven into a really strong fabric
-Resistant to abrasion
-Used in bulletproof vests and clothing for motorcyclists

211
Q

What are the properties of Nomex?

A

-Fire resistant
-Used in racing drivers’ overalls
-It has fire resistant built into the fibres so it can’t be washed away or worn away

212
Q

What are the properties of micro encapsulation?

A

-Tiny droplets of a chemical are coated in shells called microcapsules
-They are used as insect repellent, odour neutraliser or a perfume (antibacterial socks)

213
Q

What are the properties of conductive fabrics?

A

-Use fibres that can conduct electricity
-Used to integrate electronics into clothing
-Used in electronic gloves

DT (6 decks)

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