1.1 Materials and their applications

• stock form


  - the set of standard sizes in which materials are available, e.g powders, granules, sheets etc.
• what are the 2 categories of material properties?

  - mechanical properties

  - physical properties
• compressive strength (mechanical property)

  - the ability to resist crushing by pushing forces (compression)
• tensile strength (mechanical property)

  - the ability to resist stretching or pulling forces
• hardness (mechanical property)


  - the ability to resist abrasive wear, like scratching, surface indentation etc.
• toughness (mechanical property)


  - the ability to absorb impact force without fracture
• ductility (mechanical property)


  - the ability to be drawn, pulled, or extruded into a different shape
• malleability (mechanical property)


  - the ability to withstand deformation by compression without cracking
• torsional strength (mechanical property)


  - the ability to withstand twisting forces from applied torque or torsion
• shear strength (mechanical property)


  - the ability to resist sliding forces on a parallel plane
• electrical conductor (physical property)

  - allows the flow of electricity through the material
• electrical insulator (physical property)

  - does not allow the flow of electricity through the material
• thermal conductor (physical property)

  - allows the transfer of heat energy through the material
• thermal insulator (physical property)


  - prevents the transfer of heat through a material
• thermal expansion (physical property)

  - increase in volume in response to heat input
• opaque (physical property)


  - prevents light from travelling through
• translucent (physical property)


  - allows some light to pass through, but not transparent

  
• transparent (physical property)


  - allows light to pass through easily
• density (physical property)


  - the mass of a material in a given volume of space
• fusibility (physical property)


  - the ability of a material to change into a liquid or molten state when heated to its melting point
• magnetism (physical property)


  - the natural force between objects that causes the material to attract iron or steels
• corrosion/degradation resistance (physical property)


  - the ability of the material to withstand environmental attack and decay.
• classification of materials


  - metals, woods, polymers, papers and boards, composites, smart materials and modern materials.
• metals


  - ferrous

  - non-ferrous

  - alloy
• ferrous metals


  - metals containing iron

  - low carbon steel, cast iron, medium carbon steel
• non-ferrous metals


  - metals that do not contain iron

  - aluminium, copper, zinc, silver, gold, titanium, tin
• alloy


  - a mixture of 2 or more metals

  - ferrous alloys = stainless steel, die steel

  - non-ferrous alloys = bronze, brass, duralumin, pewter
• aluminium (non-ferrous)


  - malleable, lightweight, food safe, non ferrous (doesn't rust), easy to recycle, aesthetically pleasing

  - kitchen utensils, foils, cans, window frames
• woods


  - hardwoods

  - softwood

  - manufactured board
• hardwood


  - wood from a deciduous (broadleaved) tree

  - generally slow growing, lose leaves in autumn

  - oak, ash, mahogany, teak, birch, beech
• softwood


  - wood from a coniferous (evergreen) tree

  - generally fast growing, usually evergreen

  - pine, spruce, douglas fir, redwood, cedar, larch
• manufactured board


  - man-made, wood-based composite material

  - plywood, marine plywood, aeroply, chipboard, MDF
• teak (hardwood)


  - contains natural oils that resist moisture, acids and alkalis, aesthetically pleasing, hard

  - framing, cladding, decking, flooring
• polymers


  - thermoplastics

  - thermosetting polymers

  - elastomers
• thermoplastic


  - can repeatedly reheated and reshaped, so can be recycled after use

  - LDPE, HDPE, PP, HIPS, ABS, PMMA, PET, PVC
• thermosetting polymer


  - when heated undergoes chemical change, and can't be reheated and reshaped

  - UF, MF, polyester resin, epoxy resin
• elastomer


  - can be deformed under pressure at room temperature, and upon release returns to its original shape

  - natural rubber, polybutadiene, neoprene, silicone
• polyethylene terephthalate (PET) (thermoplastic)


  - thermoplastic so can be recycled, tough, transparent, impermeable to CO2

  - packaging, fabrics, plastic bottles
• melamine formaldehyde (MF) (thermosetting polymer)


  - thermosetting polymer so not affected by hot pans, chemical resistant, hard

  - flooring, decorative laminates, adhesives, kitchen worktops
• neoprene (elastomer)


  - elastomer, so e.g wetsuits will stretch and release to fit tightly around body, good degradation resistance

  - wetsuits, tubing, cable jackets