Composites And Smart Materials Flashcards
Benefits of LCDS
Require less power reducing need for replacing batteries (energy efficient)
No glare
Compact and so does not take up much room
High resolution
What are shape memory alloys?
Change shape in response to a change in temperature or electrical input.
Use of SMAs
Air conditioning
Fire alarm
Braces- nitinol changes length in response to change in temp. Be made to change at body temp so have constant tension in mouth
What are thermo-ceramics?
Metal placed in a mould under high pressure forcing particles to bond. Hard surface finish and very high melting point. Also strong and lightweight.
Hard and stable at high temperatures
Uses of thermonceramics
Turbine blades in jet engines
Brake discs
Tips on cutting tools
What is reactive glass
React to a change in temperature by changing tint
As glass gets hot the glass darkens to block heat entering through
Uses of reactive glass
Apartment windows
Glass roofing
Windows
Conservatories
What is a photochromic material?
Material that changes colour depending on light intensity to protect user or help
They block UV light
Can reduce glare
Uses of photochromic material
Welding goggles
Security markers that show under UV light
Lenses
What is a thermo-chromic material?
A material that changes colour in response to heat
Examples of thermo chromic materials?
Thermometers
Colour changing mugs and kettles
Baby spoons
Describe the layup process
Manufacture the mould (1)
• Apply release agent / polish / wax to the mould (1)
• Gel coat mixed/ resin mixed (1)
• Gel / resin coat applied (1)
• Add / spray a layer of glass fibre (1)
• Add a layer of resin
Repeat for subsequent layers (1)
• Allow to set / cure (1)
• Remove and trim
What does GTC stand for?
Quantum tunnelling composites
What is a quantum tunnelling composite?
Insulating rubber containing tiny metal particles
Pressure or force sensing
When under pressure material changes from insulating to conducting
Uses for QTCs
Touch screen technology
Speed controllers
Smart phone buttons
Name some examples of composites
MDF
Plywood
Chipboard
Glass reinforced plastic
Carbon fibre reinforced plastic
Hardboard
What are the properties of CFRP?
Lightweight
Corrosion resistant
Hard
Good compressive strength
Uses of CFRP
Sports equipment
Prosthetics
Helmets
Fishing rods
Glass reinforced plastic properties
Lightweight
Corrosion resistant
Tough
Hard
Low thermal expansion
Good compressive strength
Uses of GRP
Boat hulls
Pond liner
Sports car bodies
What is CFRP and GRP made up of?
Carbon fibres and polyester resin
Glass fibres and polyester resin
What is MDF used for?
Model or mould making
Furniture items like bookcases
‘Flatpack’ furniture
Properties of MDF
Easy to cut and shape
Good strength in all directions
Two smooth faces
Standard grade or veneered
Uses of hardboard
Wardrobe backings
Peg boards
Clipboards
Properties of hardboard
One shiny side
Does not split easily
Tough
Properties of chipboard
Composite of wood chips and urea formaldehyde
Strength in all directions
Easy to cut
Not attractive in base form
Plywood properties
Thin layers of wood placed at 90 degrees to each other and compressed
Strength in all directions
No grain weakness
Odd number of layers
Uses of chipboard
Kitchen worktops and units
Shelving
Flatpack furniture
Plywood uses
Stirctural work
Floorboards
Indoor furniture
What can composites like GRP and CFRP do that standard materials like wood and metals can’t?
Easily moulded into complex shapes using lay-up method
These shapes are lightweight with good strengthens and toughness throughout
What is nitinol an example of? What does it do?
A shape memory alloy
When heated to a certain temperature it will return to its original shape
Heat required around 70 degrees so done simply in hot water
Transition temp can be changed by supplying a current making it suitable braces in mouth without losing tension
Disadvantages of LCDs
Limited viewing angle and brightness
Requires external light source in order to see it
What does composite mean?
Material composed of different materials to maximise physical and mechanical properties
Benefits of thermochromic materials
Detect if bath too hot for kids
Detect of drink too hot
Ability to see if food is hot
Benefits of reactive glass
Retains heat, reducing heating costs
Keeps rooms cool too
Benefits of QTM technology
Maximise screen space
Remove need for buttons
Touch screen ideology
More interactive
Increased versatility
Innovative design, increases understanding of technology
Benefits of thermo-ceramics
High heat resistance (will not deform or expand)
Hard
Does not wear
Lightweight
