This document discusses the properties of materials that should be considered when selecting materials for different uses. It outlines physical properties like electrical, thermal, acoustic, magnetic, optical, and mechanical properties. Electrical properties determine whether a material is a conductor or insulator. Thermal properties indicate how materials conduct or insulate heat. Acoustic properties show if sound can pass through. Magnetic properties reveal if a material is attracted to magnets. Optical properties define if light can pass through and if objects are visible. Mechanical properties concern strength, elasticity, plasticity, malleability, and ductility. Other discussed properties include density, permeability, and impermeability. Chemical properties change the material's composition through interactions. Ecological properties
2. Material Properties
How can we choose what material
should we use?
Physical Properties
Chemical Properties
Ecological Properties
3. Physical Properties
How they react to external stimuli?
Physical Properties:
Electrical
Thermal
Acoustic
Magnetic
Optical
Mechanical
Other properties
4. Electrical Properties
We can distinguish between:
Electrical conductivity: metals.
Electrical insulation: plastic, wood,
stone, ceramics
5. Thermal Properties
How do materials behave when
heated?
Thermal conductors: metals
Thermal insulators: wood and plastic
Fusibility: Metals, some plastics and
glass.
Welding: Metals, e.g. Tin.
11. Optical Properties
Can you see light through a
material?
Opaque: Light don’t pass. Wood &
Metals.
Translucent: Light passes, but we
cannot see objects behind them clearly.
Some types of glass and plastic.
Transparent: We can see perfectly
through them: Glass and some plastics.
13. Mechanical Properties
Mechanical Strength. How the material resists
the action of forces.
Elasticity. The material returns to its original
form after a force that has changed its shape is
removed.
Plasticity. The material is permanently deformed
after a force is applied.
Malleability: Allows a material to be spread into
sheets or films.
Ductility: Allows a material to be formed into
filaments or wires
14. Other Physical Properties
Density. Relation between mass of
an object and its volume.
Permeability: Allows water or
other liquids to filter through them.
Impermeability: Doesn’t allow
water or other liquids to filter
through them.
15. Chemical Properties
When the chemical composition of a
material changes because it
interacts with other substances.
Oxidation. The material reacts with
the oxygen in the air or water. This
happens with metals, producing
rust.
16. Ecological Properties
Recyclable materials. They can be
reused (Glass, paper, cardboard, metal,
plastics).
Toxic materials. Harmful and sometimes
poisonous (Mercury, heavy metals,
petroleum).
Biodegradable materials. They
decompose naturally and don’t damage
the environment (paper, bioplastics,…)