DT Revision

DT Revision

1. Material Properties

   • Mechanical
     • A materials reaction to an applied force
   • Strength
     • A materials ability to withstand a force
   • Forces
     • Compression
       • Crushed
     • Torsion
       • Twisted
     • Tension
       • Pulled
     • Shear
       • Cut
     • Bending
       • Bend
   • Physical
     • Unchanged by forces or heat
   • Fusibility
     • Alter materials into a liquid
   • Fabrication
     • Welding or souldering
   • Thermal conductivity
     • A materials ability to tolerate heat passing through, metals
   • Insulator
     • Wood is an insulator
   • Electrical conductivity
     • Ability to toerate electricity passing through

2. WOODS

   • Softwoods
     • Conifers
     • Evergreen (Needles)
     • Quick growing
     • Relatively cheap
     • e.g. Pine and Cedar
   • Hardwoods
     • Broad leafed
     • Deciduous (lose their leaves
     • UK and the rainforest
     • e.g. Beech, Teak, Ash, Mahogany and Oak
   • Manufactured Board
     • Changing logs into a variety of forms and gluing them together
     • Large flat sheets
     • Strong
     • e.g. MDF, Plywood, Chipboard
   • Lifecycle
     • Planted
       • Cut down
         • Transported
           • Manufactures
             • Sold to retailed
               • Sold to user
                 • Recycled
   • Environment
     • Transportation
     • Factories

3. METALS

   • Ferrous
     • Contains Iron
     • Usually magnetic
     • Variable amounts of Carbon
     • e.g. Stainless Steel
   • Non- ferrous
     • Do not contain Iron
     • e.g. Copper, Zinc, Tin, Gold and Lead
   • Alloy
     • A combination of 2 or more metals
       • e.g. Brass, Bronze, Steel and Pewter
   • Lifecycle
     • Ore is extracted
       • Transported
         • Converted into metal
           • Manufactured
             • Sold to retailer
               • Sold to user
                 • Recycled or landfill

4. PLASTICS

   • Thermosetting plastics
     • Set hard
     • Permanent
     • Chemical polymers
     • e.g. Polyester resin and Epoxy resin
     • Used for kitchen surfaces
   • Thermoplastics
     • Can be remoulded
     • Most common
     • e.g. PET, PVC HDPE and LDPE
     • Used for bottles and bowls
   • Lifecycle
     • Oil is extracted from ground
       • Piped or shipped
         • Converted into plastics
           • Manufactured
             • Sold to retailer
               • Sold to user
                 • Recycled or landfill
     • Environment
       • Factories

5. Composite materials

   • GRP
     • Strands of glass fibres
       • Used for sail boats and Kit cars
     • Coated in Polyester resin
   • Kevlar
     • Like carbon fibre matting
     • Strong
     • Woven to make mat
     • Used for tennis rackets
   • Carbon Fibre
     • Strands of carbon
     • Like GRP
     • Coated in Polyester resin
     • Reinforced plastic
     • Used for track bikes

6. Smart Materials

   • Polymorph
     • For producing economic designs and models
     • e.g. Handles
   • Nanomaterials
     • Light
     • Stong
     • Stiff
     • High gloss finish
     • e.g. Jet ski hulls
   • Shape memory alloy
     • Spectacles can be returned to shape when bent
   • Thermo chromic Plastics
     • Russle Hobbs
       • A kettle that changes colour as it boils
     • Timmy Tippeee
       • Baby products that change colour if their too hot

7. Preparing Materials

   • Wood
     • Plane- To make edges flat and smooth
     • Sand with the grain
   • Metals
     • Draw filing
     • Clean surface with Emergy Cloth
   • Plastics
     • Keep the protective plastic on as long as possible
     • Use a draw file
     • Abrasive paper- Wet and Dry

8. Fittings

   • Knock down fitting
     • Often used in flat packed products
     • e.g. Corner Block
     • For being disassembled
     • Undone with a screwdriver or allan key
     • For metals and woods
   • Other Fittings
     • Variety of Fixtures
     • Magnetic
       • Sometimes visible
       • Simple
     • Bolt
       • Keeps draws shut

9. Environment

   • THE 6 R's
     • Reduce
     • Reuse
     • Recycle
     • Rethink
     • Repair
     • Refuse