Classification of Materials by its Properties
- Classification means grouping materials based on shared characteristics.
- In design, this usually involves sorting materials by their physical, chemical, or mechanical properties.
Physical Properties
Physical Properties
Physical properties are characteristics that can be observed or measured without altering the material's chemical composition.
The key physical properties include:
- Density
- Thermal Conductivity
- Thermal Expansion
- Melting Point
- Electrical Resistivity
- Electrical Conductivity
Aluminium and Copper: both share the physical property of being good conductors of electricity.
Chemical Properties
Chemical Properties
Chemical properties are characteristics that describe how a material reacts with other substances, resulting in a change in its chemical composition.
The key chemical properties include:
- Corrosion Resistance
- Reactivity (Food Safe)
- Hygroscopy
- Flammability
Glass and Ceramic are both chemically inert and non-reactive with most foods or acids.
Mechanical Properties
Mechanical Properties
Mechanical properties are characteristics that describe how a material behaves when forces are applied, such as tension, compression, bending, or impact.
Key Mechanical Properties:
- Tensile strength
- Compressive strength
- Stiffness
- Toughness
- Hardness
- Malleability
- Elasticity
- Plasticity
- Ductility
Copper and Aluminium are both ductile and can be drawn into wires without snapping.
Physical, chemical and mechanical properties will be explored in detail in the upcoming subsections.
Why Classify Materials?
- Understanding Behaviour: Classification helps predict how materials will perform under different conditions.
- Facilitating Selection: Designers and engineers can choose the right material for a specific application.
- Enhancing Communication: A common language for discussing material properties across industries.
