Materials & properties.
Choosing materials through their physical and working properties.
Why properties matter
Material selection begins with the demands of a product. A good choice needs to meet the required performance, suit the intended manufacturing process and fit constraints such as cost, appearance and environmental impact.
Mechanical properties
- Strength: ability to withstand a load without failure. Specify the type of load where possible, such as tension or compression.
- Stiffness: resistance to bending or deformation under a load.
- Toughness: ability to absorb energy before fracturing, especially under impact.
- Hardness: resistance to surface indentation, scratching or wear.
- Ductility: ability to be drawn into wire through plastic deformation.
- Malleability: ability to be shaped under compression, such as rolling into sheet.
These properties are different. A material can be hard but brittle, or strong but flexible in a particular form.
Working properties and context
Consider how a material can be cut, shaped, joined and finished. Also consider service conditions: moisture, heat, repeated loading and expected lifespan may all change the best choice.
Exam connection
Give a property, link it to a specific requirement, then explain the benefit. “Aluminium is suitable” is too vague. “Aluminium’s low density reduces the mass of a portable product, making it easier to carry” is more precise.
Remember: the best material depends on the product brief, not on one property in isolation.