Chapter 5. Materials and Their Properties
Common material groups [10]:
| Group | Examples | Typical features |
| Ferrous metals | Cast iron, mild steel, tool steel, stainless steel | Strong and durable; most rust unless protected |
| Non-ferrous metals | Aluminium, copper, brass, bronze, zinc | Lighter or more corrosion resistant; many conduct electricity well |
| Wood | Softwood (pine), hardwood (teak, oak), plywood, MDF | Easy to work; varies with moisture and grain |
| Plastics | Thermoplastics (PVC, polyethylene), thermosets (epoxy, phenolic) | Light, corrosion resistant, can be moulded |
| Ceramics and glass | Bricks, tiles, porcelain, glass | Hard, brittle, heat resistant |
| Composites | Fibreglass, reinforced concrete, carbon fibre | Combine properties of different materials |
Steel is iron with a small amount of carbon; more carbon makes steel harder but more brittle. Stainless steel contains a high proportion of chromium that resists corrosion [10].
Mechanical properties: strength (resistance to force), hardness (resistance to indentation), toughness (ability to absorb impact), ductility (ability to be drawn into wire), malleability (ability to be hammered into shape), elasticity and brittleness [10][11].
Other properties: density, thermal and electrical conductivity, melting point and corrosion resistance.
Heat treatment of steel (hardening, tempering, annealing) changes hardness and toughness.
Corrosion and protection. Rust is the corrosion of iron in the presence of oxygen and moisture. Protect by painting, galvanizing (zinc coating), oiling, plating or choosing corrosion-resistant materials.
Choosing materials. Consider strength, weight, cost, availability, machinability, appearance, environment and safety, and recycle or dispose of scrap properly [10].
Review: Which property describes a material’s resistance to being scratched or indented? (Answer: hardness.)