DT: materials

what are the properties of smart materials?
Often react to the environmental conditions such as heat, light and movement
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what does the term mechanical mean?
it is how a material will react to physical forces such as some materials becoming brittle when repeatedly bent or flexed
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What does the term electrical mean?
it is a material's conductive properties such as insulation and resistanceE.G. Screwdriver's polymer handle(insulator) so it will not shock the user through the tip as metal used is a (conductor)
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What does the term chemical mean?
How a material reacts to other chemicals such as how metals oxidise when exposed e.g. ferrous metals rusting
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What does the term thermal mean?
how a material responds to different temperatures and boiling points such as the temperature ranges where thermoforming plastics can be shaped
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What does the term magnetic mean?
Most ferrous(containing iron)as materials are attracted to magnets or can be magnetised. For a magnetic door catch
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What does the term permeability mean?
the degree to which liquids or gases can pass through a material such as woods that have been varnished having low permeability to liquids and water resistance
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What does the term aesthetic mean?
the visual properties of the surface/form of a material e.g. colour and shine
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What does the term tactile mean?
the touch of a material such as texture
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What is meant by the term strength?
the ability to withstand a constant external force without failing
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What is meant by the term hardness?
the ability to resist wear and tear, scratching and dents
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What is meant by the term toughness?
the ability to withstand blows or momentary shocks
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What is meant by the term durability?
The ability to resist wear e.g. weathering over time
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What is meant by the term elasticity?
The ability to bend and return to it's original shape
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What is meant by the term plasticity?
The ability to permanently change shape or form, which applies to materials other than polymers
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What is meant by the term malleability?
The ability to change shape in all directions while retaining integrity
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What is meant by the term ductility?
The ability to permanently change shape by stretching along its length without snapping
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When selecting materials what must be taken into consideration
1requirements for the user2function or conditions product is exposed to3materials can be found by using a materials database
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what is meant by the term shape memory alloy
alloy of nickel and titanium that returns to original shape when hearted over 90C +contracts when current passed through itUSES: stents and dentures
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what is meant by the term shape memory polymer
a variety of polymer(plastics) that deform when an electric voltage is applied or change in temp USES:valves or pumps for liquids where mechanical components are not desirable
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what is meant by the term thermochromic inks
change in colour in response to changes in temp USES: forehead thermometer strips and to indicate temperature of a packaged food product in the food industry
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what is meant by the term photochromic inks
change in colour in response to changes in light levelUSES: Light reacting sunglasses
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what is meant by the term lenticular sheet
an embossed polymer sheet with optical fibres that make a surface appear deeper+can make images appear to flicker or moveUSES: used to provide visual/aesthetic interest to a surface such as the illusion of depth and 3d effects
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what is meant by the term polymorph
small pellets which fuse when heated to 62C and can be moulded resulting in a tough polymerUSES: used by designers and engineers to prototype difficult shapes such as components and handles
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what is meant by the term smart grease
A viscous gel which will uniformly control the movement between two friction surfacesUSES: used to dampen movement on volume control knobs slowing and smoothing rotation
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what are the two types of synthetic polymer
thermoforming and thermosetting
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what is meant by the term Nylon
used as a fibre in clothing+common+resists abrasion has low friction characteristics and good chemical resistance and is applied as a mechanical component such as gears, bushes and cams and in toothbrush files
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what is meant by the term low and high density polyethylene
Tp is low density polyethylene is less expensive+High density polyethyle is more expensive and is available+injection and blow moulding bottles and containers
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What is meant by the term polyethylene terepthalate
Hard,stiff strong and stable with low water absorption+good chemical resistanceUSES signs, drinks bottles and smart cards
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what is meant by the term polyvinyl chloride
good resistance to chemicals and solvents+good tensile strength also resistant to water and fireUSES=rain,water and sewage pipes
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what is meant by the term acrylic
hard with reasonable tensile strength and good resistance to UV light and weatherUSES=bathroom furniture and aircraft anopies
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what is meant by the term polystyrene
poor resistance to UV light and commonly used USES toys, light fittings, computer cases
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What is meant by the term polypropylene
high resistance to chemicals and highly flexible and resistant to stress USES=chemical containers and tanks, fuel cans
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what is meant by the term acrylonitrile-butadiene-styrene(ABS)
durable, weather and chemical resistant rubber like so good impact resistanceUSES=boat hulls telephones
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what is meant by the term melamine formaldehyde
Clear, hard and chemical resistant thermosetting resinUSES=electrical plugs, switches and sockets
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what is meant by the term Urea formaldehyde
high tensile strength and surface hardness low water absorptionUSES=buttons, toilet seats and electrical fittings
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what is meant by the term Phenol formaldehyde
A synthetic polymer with high hardness, good thermal stability and chemical resistanceUSES=laboratory worktops and billiard balls
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what is meant by the term polyester resin
stable, low cost and easy to use, good chemical resistance and electrical propertiesUSES=glass reinforced for boat hulls, car body panels and printed circuit boards
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what is meant by the term epoxy resin
high adhesive strength and mechanical properties as well as high electrical insulationIUSES=adhesives, coatings and printed circuit boards
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how is rift sawn cut
pic
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how is quarter sawn cut
pic
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how is plain sawn cut
pic
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Other cards in this set

Card 2

Front

what does the term mechanical mean?

Back

it is how a material will react to physical forces such as some materials becoming brittle when repeatedly bent or flexed

Card 3

Front

What does the term electrical mean?

Back

Preview of the front of card 3

Card 4

Front

What does the term chemical mean?

Back

Preview of the front of card 4

Card 5

Front

What does the term thermal mean?

Back

Preview of the front of card 5
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