Properties of Materials
At some point in the design process, material will have to be chosen.
The advance of knowledge and the development of material science provide the designer with a far better choice than ever before. To be better informed about materials should lead to better choices and better products.
A designer may be looking for a component that:
has good grip, or
will provide strength but remain flexible, or
is resistant to bacteria.
Knowing that there are appropriate materials with the properties that are required, is a step in the right direction.
This does not mean that designing something starts when all knowledge about materials has been collected.
Most importantly, the early part of the design process will rarely require detailed decisions about materials.
There may also be other constraints:
some materials may not be available,
certain materials may be banned because of the danger of fumes, dust, chemical reaction or content,
they may require specialist equipment or processes that are not available.
Consequently, the specific knowledge about a suitable material may be more appropriately collected and considered after some initial ideas have been recorded. The information is then relevant, focused and likely to be of specific use to further design development.
The guide shown below is intended to provide an aid to making design decisions and material choices.
|Hardness||Will resist wear, being scratched or dented. (Surfaces)|
|Strength||Will resist forces, (tension, compression, shear, torsion, bending)|
|Stiffness||Will resist being distorted from its original shape or form|
|Brittleness||Has hardness property throughout and shatters when it fails.|
|Toughness||Has combined resistance to damage but can be flexible.|
|Ductility||Can maintain and be easily shaped and formed.|
|Conductivity||Allows various energy forms to be resisted or encouraged to flow.|
|Optical||Noticeable reflection or transmittance of light|
|Absorption||Allows energy or substances to be stored.|
|Light or heavy||Less or more|
|Visual||Provokes sensual qualities|
|Conversion||Ease of shaping, forming, cutting, bending, mixing and joining.|
|Hygienic||Resistance to unhealthy influences|
|Disposal||Energy efficient and environmentally safe.|
It should be remembered that some properties may be undesirable and choices should be made accordingly.
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