Developments in new materials Flashcards
what is a modern material
a material that has been engineered to have improved properties
examples of modern materials
Concrete, aluminium and steel, graphene, titanium, metal foams
properties of graphene
- single carbon layer material
- very strong, 100x stronger than steel
- light
- good conductor of heat and electricity
- used in tennis rackets
properties of titanium
- corrosion resistant
- high strength to weight ratio
- difficult and therefore expensive to machine
- used for bone replacements, bikes, ships, armour
properties of metal foams
- metal foam is a metal that contains many gas filled spaces which make it LIGHTWEIGHT
- stiff
- tough
- strong under compression
- used in lightweight car parts(as they can absorb shock) and bone implants
properties of LCDs
- used in flat screen displays
- thin
- lightweight
- energy efficient
- originally used in calculators
- high definition displays
how do LCDs work in a display
- the liquid crystals used in the display are made of a mixture of chemicals
- when an electrical current is passed through, the crystal shape is modified
- this changes the image seen on the screen
properties of nanomaterials
- made out of nanoparticles
properties of carbon nanotubes
- high strength to weight ratio
- good conductors of heat and electricity
- can be added to a material to strengthen it without adding much weight
properties of self cleaning fabrics
have a nanoparticle coating that removes odours and stains upon exposure to light
properties of antibacterial fabrics
use nanoparticles of silver to kill bacteria, also have medical uses like face masks and dressings
properties of coated metals
- iron and steel can be galvanised to prevent rusting, they can also be elctroplated
what is anodised aluminium
has a coating of aluminium to make the surface harder and resistant to corrosion
PVC coated metals
metals like steel can be coated with PVC to make it corrosion resistant
what is a smart material
materials that change their properties in response to a stimuli
what are shape memory alloys
metal alloys that can remember their shape when heated
examples of shape memory alloys
- nitinol, used in glasses, if you bend them by accident and heat them in a bowl of hot water, and they’ll jump back into shape
- braces also made using nitinol, are warmed up in the mouth and ‘pull’ on the teeth, so they move with the nitinol
what are thermochromic pigments
used in colour changing products, they react to temperature
- when temperature increases, the product changes colour, the colour changes back when the object returns to its original temperature
uses of thermochromic pigments
babies feeding spoons, so parents know the food isn’t too hot
what are photochromic pigments
things that change colour in response to light
examples of photochromic pigments
spectacle lesnes, go dark (turn into sunglasses) in dark light, but go back to bright when in light
- photochromic inks can be used to print t shirts with designs that only show in sunlight
what are composite materials
a combination of two or more materials to improve properties
examples of composite materials
- Glass reinforced plastic (GRP)
- Carbonfibre reinforced plastic (CRP)
properties of GRP
- Glass fibres coated in thermosetting plastic resin
- strong
- tough
- heat resistant
- easy to mould into complex shapes
