GCSE Engineering AQA

Materials and their Properties

Section 1: Types of Materials

• Ferrous Metals: These are iron-based metals that often have a magnetic property. They include steel and iron.

• Non-Ferrous Metals: These are metallic materials not based on iron and they do not have a magnetic property. Examples include copper, aluminium, and brass.

• Polymers: These are organic, synthetic materials such as plastics. They are recognised for their flexibility and insulating properties.

• Ceramics: Ceramics encompass traditional clay ceramics, as well as modern advanced ceramics. They are hard, strong, and can withstand high temperatures and pressures.

• Composites: These are made from two or more constituent materials with significantly different physical or chemical properties. The new material has characteristics different from the individual components.

Section 2: Properties of Materials

• Physical Properties: Consider elements such as colour, density, and melting point.

• Mechanical Properties: These cover hardness, tensile strength, ductility, toughness, and fatigue strength.

• Chemical Properties: Understanding how the material reacts with others, its corrosion resistance and how it behaves under certain conditions is key.

Section 3: Choosing Materials

• Application Suitability: The choice of material greatly depends on its intended application. Consider factors such as the material's strength, longevity, and cost.

• Environmental Impact: When choosing materials, their environmental impact must be evaluated. This includes their energy consumption during manufacture and their recyclability.

• Aesthetic Appeal: A material's appearance, texture, and colour may also influence choice, especially in design-focused engineering projects.

Section 4: Material Testing

• Hardness Testing: Measures a material's resistance to permanent shape change when a compressive force is applied.

• Tensile Testing: Evaluates a material’s ability to withstand forces that would pull it apart.

• Impact Testing: Investigates a material’s ability to withstand a high force or shock applied over a short time period.

• Fatigue Testing: Assesses how a material performs under repeated loads, often over long periods of time.

Section 5: Material Processing

• Forming: The process of creating parts and components from raw materials. This can involve plastic deformation techniques like forging, bending, and stamping.

• Joining: The bigger structures are often an assembly of smaller parts. The techniques used to join these objects include welding, riveting, screwing or using adhesives.

• Finishing: After a piece has been formed or joined, it may undergo a finishing operation to improve the appearance or performance. This could be painting, plating, or a heat treatment process.