Introduction to Engineering Materials
- Engineering materials are substances used in the creation of systems or mechanisms.
- These materials have specific properties which make them useful for particular applications in engineering.
- Materials can be classified into main groupings: metals, polymers, ceramics, and composites.
- Metals are often used in engineering due to their strength, durability and malleability.
- Examples of metals used in engineering include steel, aluminium, copper, and iron.
- Specifically, steel is often used for its high tensile strength and durability, while aluminium is preferred for its light weight.
- Polymers are commonly used in the creation of plastics and rubbers.
- They can be lightweight and flexible, with good insulation properties.
- Common engineering polymers include polyethylene, polypropylene, and polyvinyl chloride (PVC).
- Ceramics are typically hard and brittle materials, which have high heat and electrical resistance.
- They are often used for insulating electrical devices or for their heat-resistant properties in applications such as aerospace.
- Examples of ceramics include porcelain, brick, and glass.
- Composites are made from two or more constituent materials with significantly different physical or chemical properties.
- These materials work together to create a substance with characteristics different from the individual components.
- An example is fibre-reinforced plastic (FRP), where fibres provide strength and flexibility, while the plastic binds and protects the fibres.
Importance of Properties
- Every material has a set of properties that can include hardness, strength, elasticity, ductility, melting point, and thermal conductivity.
- Engineers must understand these properties to make informed decisions when selecting materials for specific applications.
- The cost-effectiveness of a material is another important factor in material selection.
Testing of Materials
- Engineers conduct material testing to determine the suitability of a material for a specific application.
- Testing methods can include tensile testing, compression testing, hardness testing, and impact testing.
- The results of these tests provide engineers with valuable information about a material’s properties and potential performance.
Sustainability and Engineering Materials
- There is a growing emphasis on sustainability in engineering.
- Engineers are expected to make choices that minimize environmental harm, which can include choosing recyclable materials or materials with a lower carbon footprint.
- Recycled materials, such as scrap steel or aluminium, can be just as effective as new materials, but with a much smaller environmental impact.