RM Materials

RM Materials

1. Woods

   • hardwoods
     • oak
       • Light brown colour, strong, hard, tough, open-grained, corrodes steel screws and fittings
     • mahogany
       • Pink to reddish-brown colour, fairly strong, durable, some interlocking grain
   • softwoods
     • pine
     • birch
   • man-made
     • mdf
     • plywood

2. metals

   • non ferrous
     • aluminuim
       • Good strength-to-weight ratio, light, soft, ductile, good conductor of heat and electricity
     • Copper
       • Malleable and ductile, good conductor of heat and electricity, resistant to corrosion
   • ferrous
     • steel
       • Tough, ductile, malleable, good tensile strength, poor resistance to corrosion
     • iron
       • Hard skin, softer underneath, but brittle, corrodes by rusting
   • alloys
     • stronger mix of metals

3. plastics

   • thermosetting
     • Nylon
       • Creamy colour, tough, fairly hard, resists wear, self-lubricating, good resistance to chemicals and machines
     • Acrylic
       • Stiff, hard but scratches easily, durable, brittle in small sections, good electrical insulator, machines and polishes well
   • thermoplastics
     • epoxy Resin
       • Good electrical insulator, hard, brittle unless reinforced, resists chemicals well
     • Polyster Resin
       • Stiff, hard, brittle unless laminated, good electrical insulator, resists chemicals well

4. ceramics

   • made from clay
   • Ceramics are made from clay, sand and feldspar. These materials are ground to a fine powder, mixed together and fired at high temperatures (700-2000°C).

5. Smart Material's

   • Smart materials are reactive materials. Their properties can be changed by exposure to stimuli, such as electric and magnetic fields, stress, moisture and temperature.

6. Properties of Materials

   • conductivity is the ability of a material to conduct heat or electrical energy
   • strength is the ability of a material to withstand a force without breaking or bending
   • elasticity is the ability of a material to bend and then to return to its original shape and size
   • plasticity is the ability of a material to permanently change in shape
   • ductility is the ability of a material to deform, usually by stretching along its length
   • malleability is the ability of a material to permanently deform in all directions without cracking
   • hardness is the ability of a material to resist wear, scratching and indentation
   • toughness is the ability of a material to withstand blows or sudden shocks without breaking
   • durability is the ability of a material to withstand wear, especially as a result of weathering
   • fusibility is the ability of a material to change into a liquid or molten state when heated to its melting point

7. Smart Colours

   • Smart colours are pigments which can be incorporated into paints, dyes, inks and plastics