Product Design Paper 1

Mechanical Properties

Mechanical Properties

How a material reacts to an external force

Physical Properties

The actual make up or structure of the material

Compressive Strength

Mechanical Property - The ability to withstand being crush or shortened by pushing forces

Tensile Strength

Mechanical Property - The ability to resist stretching or pulling forces

Bending Strength

Mechanical Property - The ability to resist forces that bend the material

Shear Strength

Mechanical Property - The ability to resist sliding forces on a parallel plane

Torsional Strength

Mechanical Property - the ability to withstand twisting forces

Hardness

Mechanical Property - the ability to resist abrasion like scratching

Toughness

Mechanical Property - the ability to withstand impacting forces without fracture

Plasticity

Mechanical Property - the ability to be permanently deformed and retain that shape

Ductility

Mechanical Property - the ability to be drawn into a wire

Malleability

the ability to withstand deformation through compression

Elasticity

Mechanical Property - the ability to be deformed and then return to the original shape

Electrical Conductor

Physical Property - materials that allow an electrical current to flow through it

Electrical Insulator

Physical Property - a material that doesn’t allow an electrical current to flow through it

Thermal Conductor

Physical Property - a material that allows the transfer of heat energy

Thermal Insulator

Physical Property - a material that doesn’t allow the transfer of thermal energy

Opaque

Physical Property - prevents light from travelling through it

Translucent

Physical Property - a material that allows light through but diffuses it so that objects seen through it appear blurred - e.g. frosted glass

Transparent

Physical Property - material that allows light to pass through it

Density

Physical Property - mass/volume

Fusibility

Physical Property - the ability for a material to be transferred from a solid to a liquid

Magnetism

Physical Property - the possession of a natural force which causes the material to be attracted to other ferrous metals

Corrosion

Physical Property - the ability to be degraded by the environment e.g. through rain

Ferrous

Metals that contain iron. Usually have high carbon contents, are magnetic and will rest e.g. steel and cast iron

Non-Ferrous

Metals that don’t contain iron. Not magnetic and don’t rust e.g. zinc and aluminium

Alloy

A metal made from two or more metals. Ferrous alloys are ones that contain iron (such as steel) while Non-Ferrous alloys are ones that don’t contain iron like bronze

Hardwood

Wood from deciduous trees - drop their leaves. Slower growing and therefore more expensive but better properties: tighter grain makes it much more durable than soft wood and more resistant to water and pests

Softwood

Wood from coniferous trees (evergreen and produce cones). Faster growing and therefore cheaper but a loose grain makes it less durable and vulnerable to water and pests

Manufactured Boards

A man made composite material based from wood. Available in much larger sizes and don’t contain the blemishes of natural wood.

Purpose of Veneers

Produce the aesthetic of natural wood with the grain but mean the product can have the physical qualities of manufactured boards - available in larger stock forms, cheaper and without natural blemishes.

Thermoplastics

Polymers that can be repeatedly reheated and reshaped allowing it to be recycled e.g. HIPS and HDPE

Thermosetting Plastics

Polymers that when heated experience a chemical reaction where the molecules form strong bonds. This means that products using this type of polymer can’t recycled and reshaped. e.g. epoxy resin

Elastomer

A material which at room temperature can be deformed under pressure and then return to its original shape e.g. natural rubber and silicone

Which polymer is used to create drinks bottles

Polyethylene terephthalate (PET)

A thermoplastic which means it can be recycled

Why is Aluminium a good material

• malleable - can easily be formed into shape

• lightweight - easy to lift and transport

• non-ferrous - so won’t rust when in contact with the liquid it holds

• recyclable

Example of a thermosetting polymer

Melamine Formaldehyde - used for kitchen surface tops - won’t be affected by hot pans being placed on it