29-10-2012, 11:51 AM
Materials Technology Classification of Materials
Materials Technology.ppt (Size: 2.28 MB / Downloads: 236)
Classification of Materials
Plastics
Wood
Composites
Ceramics
Metals
Fabrics
Classification of Materials (Composites)
A composite is a combination of two or more chemically distinct materials whose physical characteristics are superior to its constituents acting independently.
Because of their high strength/stiffness to weight ratio they are widely used in the;
Aerospace industry
Offshore structures
Boats
Sporting goods
Classification of Materials (Ceramics)
Ceramics are compounds of metallic and non-metallic elements, examples include;
Oxides (alumina – insulation and abrasives, zirconia – dies for metal extrusion and abrasives)
Carbides (tungsten-carbide tools)
Nitrides (cubic boron nitride, 2nd in hardness to diamond)
Classification of Materials (Smart Materials)
A smart material can be described as a material that has a useful response to external influences or stimuli.
There are many examples of smart materials in everyday use that are not modern developments they include;
Metal springs
Light bulbs self regulate because as
The filament temperature increases
their resistance rises
Ancient civilisations have long used
porous ceramics for self regulating cooling