unit 5 composite materials Flashcards
mechanical properties
tensile and compressive strength
stiffness and toughness
plasticity and elasticity
ductility and malleability
physical properties
mass,wieght,volume
density and harness
electrical and thermal conductivity
what is tungsten carbide
composite material
made from ceramic and metal
hard, rigid,impact resistant
used in high speed cutting tools
carbon fiber
lightweight, high tensile strength
corrosion/chemical resistant
stable in hot conditions
used in racing cars
glass reinforced platic
strong in tension
little compressive strength
lightweight
uv/corrosion/water resistant
aluminium composite boards
easy to cut
stable, durable,lightweight
range of colours, wont wrap/wrinkle
used in wall panels
fiber cement
was made from cement, asbestos
now made from cellulose and synthetic fibres
lightweight,durable,weather/chemical/rust resistant
used in cladding
concrete
made from air, cement,water,sand,gravel
heavy, high compressive strength,cheap
used in buildings
steel reinforced concrete
used in high rise buildings, bridges and multi story car parks
smart material
one or more properties that is dramatically altered by an external stimulus
shape memory alloys
programmed to remember specific shape at certain temperature
expensive
weather/temp/electrical current stimuli
thermochromic pigment
changes colour/opoacity with change in temp
temp stimuli
phosphorescent pigment
glow in the dark
material absorbs energy from light and emits light in the dark
used in toys paints stickers
light stimuli
photochromic pigment
smart material that changed colour/opacity with uv light in a reversible reaction
used in spectacles, clothing
light stimuli
electroluminescent wire
copper wire coated in phosphor glows when alternative current is applied
flexible, can be used outdoors
used in lighting,bikes,vechicles
electrical current stimuli
piezoelectric materials
convert mechanical energy into electrical
can be stored
used to create spark in lighters
pressure stimuli
What kind of external stimuli might affect a smart material?
Temperature
Moisture
Light Levels
Pressure
what is kevlar
high performance aramid fiber
properties of kevlar
bullet proof, heat and chemical resistant,lightweight,hardwearing,strong,stiff
what is polymorph
thermoplastic which becomes malleable when heated to 62
properties of polymorph
tough durable non toxic biodegradable low melting point
uses of polymorph
enhanced ergonomic designs
moulds and gum shields
what is precious metal clay made of
from precious metal particles held in a water based non toxic binder
properties of pmc
What does PMC stand for?
Precious Metal Clay
What are the uses of PMC?
used to set stones and join PMC parts
What are the properties of HDMF?
lightweight and easy to handle
soft so cuts easy
dented easily
paint and glue will dissolve hdmf
holds good surface detail and fillers
what does HDMF stand for?
High Density Modelling Foam
What is HDMF used for?
makes molds for vacuum forming
What is shape memory alloys used for?
Nitinol
example of thermochromic pigment?
varnishes
kids cup
Phosphorescent examples
fire exit signs
electroluminescent examples
veichles and bikes
piezoelectric examples
crystal
ceramic
bone
What is Tungsten Carbide?
Composite material made from ceramic and metal, known as a cermet.
What are the main properties of Tungsten Carbide?
Extremely hard, rigid, and impact resistant.
How many times harder than steel is Tungsten Carbide?
100 times.
What can scratch Tungsten Carbide?
Only a diamond.
What is a key advantage of Tungsten Carbide at extreme temperatures?
It retains its properties, making it ideal for high-speed cutting tools.
Name two applications of Tungsten Carbide.
Premium kitchen knives, surgical instruments, and jewellery.
What process allows Tungsten Carbide to be formed into complex 3D forms?
Sintering.
Fill in the blank: Tungsten Carbide is known as a _______.
[cermet].
True or False: Tungsten Carbide is less rigid than steel.
False.
What are carbon fibres?
Carbon fibres are several times thinner than a human hair.
What are the properties of carbon fibres?
They are lightweight and have high tensile strength.
How are carbon fibres used?
Fibres are woven into a fabric; the more complex the weave, the more durable the material will be.
What is carbon fibre composite?
Carbon fibre composite is the combination of carbon fibre with a resin, such as vinyl ester or epoxy.
What is Carbon Fibre Reinforced Plastic (CFRP)?
A material used for high tech bike frames, sports equipment, racing cars, crash helmets, and prosthetics.
What are the key properties of CFRP?
Corrosion and chemical resistant, lightweight, stable in hot conditions, tough, hardwearing, and has good tensile strength.
Why is CFRP suitable for wind turbines?
It offers significantly improved stiffness, strength, and fatigue resistance per unit mass compared to fiberglass.
What is GRP commonly known as?
GRP is commonly known as Fibreglass.
What materials are combined to create GRP?
Thermosetting plastics such as polyester or epoxy resin are combined with fibres made of glass.
What are the properties of glass fibres?
Glass fibres are strong in tension with little compressive strength.
What are the properties of resins?
Resins are strong in compression but weak in tension.
What is the result of combining glass fibres and resins?
The combination results in a material that has strengths and weaknesses in tension and compression.