Mock Revision Flashcards
what’s the definition of wasting?
any process that involves removal or wasting of material
whats an example of wasting?
laser cutting, drilling, lathe work, punching
whats the process that involves changing or manipulating materials WITHOUT melting?
deformation
whats an example of deformation?
vacuum forming, steam bending, rolling, line bending
what is the definition of redistribution?
any process involving melting and then cooling to form a solid object.
whats an example of redistribution?
injection moulding, split pattern casting, extrusion
what is the definition of fabrication?
ay process involving joining parts together to make a whole product.
what are lamination, riveting, and welding examples of?
fabrication
what is the definition of hardwood?
Timber from Broad leaved (Deciduous) trees.
Trees that lose their leaves in Autumn.
Generally producing stronger, harder and more durable timber but slower growing.
what is the definition of softwood?
Timber from Coniferous (cone bearing) trees.
Trees that keep their needles / leaves all year and are considered evergreen.
Generally faster growing.
what are some examples of hardwood?
oak, ash, mahogany, beech, birch
what are some examples of softwood?
pine, spruce, cedar
define ergonomics?
design elements that help a product interact with a human
what are common good ergonomic design features?
grips that fit the hand, rubber grips, buttons easily accessible, visibility, contrasting colours, good balance
what are the uses of softwood?
cheap quality furniture, simple joinery, indoor work including bedroom and bathroom furniture, windows
what are the uses of hardwood?
high quality furniture, tool handles, flooring, outdoor furniture (long term)
which type of wood is coniferous?
softwood
what type of wood is deciduous?
hardwood
what is a smart material?
a material whose physical properties change in response to a change in the environment. for example electricity, pressure, temperature, light.
what is a SMA( shape memory alloy)?
a material that changes shape in response to temperature or electrical input.
where are shape memory alloys used?
dental braces, self closing windows, plane wing flaps, stents, bone plates etc.
what is thermochromic pigment/paint?
a material that changes colour in response to a temperature change.
where is thermochromic pigment/paint used?
baby spoons, bath monitors, thermometers, mugs and kettles etc.
what is phosphorecent pigment/paint?
a material that absorbs and re emits light ie glow in the dark
whhere is phosphorecent pigment/paint used?
fire exit signs, glow in the dark products, watch hands/faces, nightlights.
what are the good properties of aluminium?
Advantages:
- Lightweight for it’s strength
- Corrosion resistant compared to other metals (self forming oxide layer - anodizing principle
- Readily available - a very common element (bauxite)
- Highly recyclable and recycled
- Low melting point - cheaper energy costs for casting etc
- Easy to machine (softer than other metals)
- Good thermal conductor (heat sinks, casings that need to dissipate heat - e.g. engine blocks etc )
- Average electrical conductor (good copper substitute for cheaper items)
- Highly polishable
- Ductile & Malleable in certain forms.
what are the bad properties of aluminium?
Disadvantages:
- Low hardness - not good for wearing surfaces/bearings etc
- Low tensile strength compared to steel
- Low toughness - Tends to crack rather than bend under sudden impact
- Low melting point (680C) - makes it unsuitable for some components (e.g jet engines)
- High initial extraction cost compared to other metals (requires large amounts of electricity
- Tricky to weld - needs annealing post welding to maintain strength or pre-heating before welding
-Needs to be alloyed with other materials to make it useful - usually magnesium -Raw Aluminium is very brittle and a poor material - the material you all associate Aluminium is actually Duralumin - an alloy.
what are properties of steel and how is that useful?
- germicidal -> useful for kitchenwear
- non corroding -> used outdoors in cars, railroads etc
- good thermal conductor -> used for pots and pans
- self finishing -> great for mass production
- easily polished and maintains a shine -> aesthetics
- hard and high tensile strength/toughness relative to other metals -> used for building
what is the process of anodizing?
(LEARN DIAGRAM)
1) the part is etched/cleaned in sulfuric acid.
2) the part to be anodized is then made the anode in a DC electrical circuit where current is passed through an electrolyte solution.
3) This causes oxygen to leave the electrolyte and build up as an oxide layer on the anode (the part) as hydrogen is given off at the cathode.
4) The oxide layer is then porous and harder than the base metal underneath.
5) The part is removed from the electrolysis tank and placed in a coloured dye, which absorbs into the oxide layer giving the part a colour.
6) The part is then placed in boiling water to seal up the pores and trap the dye inside the layer.
what are the benefits of anodizing?
- > very hard finish compared to spray paint - wont scratch as easily or chip like paint.
- > fairly easy to automate in a factory setting - for mass production.
- > can anodize hard to reach areas that paint may not get to.
- > acts as a barrier to corrosion - whereas corrosion can get below paint layer.
what are the drawbacks of anodizing?
- > Chemicals involved in manufacture .
- > Limited range of colours/shades .
- > Can be time consuming for one off jobs.
