composites and modern/smart materials Flashcards
what is a composite?
two or more materials are combined together by some kind of bonding to enhance mechanical, functional and aesthetic properties.
what is fibre cement used for?
cladding / roofing
what are the advantages of fibre cement?
durable, lightweight, smooth finish, noise insulator
what is GRP?
glass reinforced plastic - also known as fibreglass
what are the advantages of GRP?
high compressive / tensile strength, lightweight
what is CFRP?
carbon fibre reinforced plastic
what is CFRP used for?
racing cars, bike frames
what are the advantages of CFRP?
lightweight, corrosion and chemical resistant
what composite is woven into fabric?
carbon fibres
what three properties do composites enhance?
physical, mechanical and working
what is tungsten carbide made from?
ceramic and metal (cermet)
what is tungsten carbide used for?
surgical instruments, drill bits, kitchen knives
what are the advantages of tungsten carbide?
extremely hard, rigid and impact resistant
what is concrete made up of?
air (6%), cement (10%), water (18%), sand (25%), gravel (41%)
what is steel reinforced concrete used for?
high rise building, bridges
what is a disadvantage of steel reinforced concrete?
it can be broken by strong weather
what is a modern material?
a material that has been developed by engineers and scientists through research and experimentation
what is kevlar used for?
bulletproof vests, high performance vehicles
what is polymorph an example of? what is it’s application?
modern material (thermoplastic that is malleable at low temperatures)
gum shields
what is precious metal clay used for?
jewellery
what are the pros of using precious metal clay?
easy and quick to work with and can be fired in a kiln
what is high density modelling foam an example of?
modern material
what is high density modelling foam used for?
moulds for vacuum forming and casting metals at low temperatures
what is a smart material?
they have one or more property that can be dramatically altered by external stimulus
what is an application of shape memory alloy?
glasses frames
what is a shape memory alloy?
a smart material that can be bent out of shape and will return to its programmed shape at a given temperature (activation temperature which stimulates reforming)
to initially shape, it must be heated above the transformation temperature
what is thermochromic pigment?
it changes colour or opacity with a change in temperature
what is phosphorescent pigment?
glow in the dark (responds to light)
what is photochromic pigment?
a smart material that changes colour or opacity with the level of ultraviolet light in a reversible reaction
what is electroluminescent wire?
material made from copper wire coated in phosphor which glows when an alternating current is applied to it
what are piezoelectric materials?
they convert mechanical energy into electrical energy and vice versa
which smart material converts mechanical energy into electrical energy and vice versa?
piezoelectric materials
which smart material is made from copper wire coated in phosphor which glows when an alternating current is applied to it?
electroluminescent wire
which smart material reacts to levels of ultraviolet light?
photochromic pigment
which smart material is referred to as ‘glow in the dark’?
phosphorescent pigment
which smart material changes colour / opacity with a change in temperature?
thermochromic pigment
which smart material is ‘programmed’ to remember a specific shape?
shape memory alloys
what is quantum tunnelling composite?
when in a relaxed state, it is an electrical insulator but when compressed, stretched or twisted, it becomes an electrical conductor
what is aluminium composite board?
combines a polymer core faced with a thin sheet of aluminium
positives of aluminium composite board?
- available in a wide range of colours and finishes
- won’t expand / contract in extreme weather
- doesn’t warp / wrinkle over time
what is an advantage of using high density modelling foam?
- rigid
- lightweight
- strong material
