Engineering materials and their properties

Engineering materials and their properties

Engineering Materials

Metals

  • Ferrous metals like iron and steel are magnetic and corrode easily, the latter having greater strength due to carbon content.
  • Non-ferrous metals like aluminium and copper are non-magnetic and resistant to corrosion. Aluminium is known for its light weight.
  • Alloys such as stainless steel or brass have combined properties of their constituent metals. Stainless steel is corrosion-resistant while brass has desirable acoustic properties.

Polymers

  • Thermoplastics, like acrylic and polyethylene, soften when heated, making them ideal for mass manufacturing.
  • Thermosetting plastics, like epoxy resin and melamine, are permanently hard and maintain their shape even under high heat. They demonstrate electrical insulation and are resistant to chemicals.

Ceramics

  • Materials like porcelain, bricks and glass exhibit strong compression strength and resistance to heat, but are brittle.
  • Advanced ceramics like aluminium oxide and silicon carbide display extreme hardness and thermal stability, suitable for high-stress environments.

Composites

  • Materials such as fibreglass, carbon fibre and Kevlar are made of two or more distinct substances which retain their individual characteristics while also gaining new properties. Frequently lightweight and have high tensile strength.

Material Properties

Mechanical Properties

  • Hardness: Resistance of a material to scratching or indentation.
  • Strength: A material’s ability to withstand stress without deformation. Includes tensile strength, compressive strength, and shear strength.
  • Malleability: Capacity to be bent or flattened without cracking or breaking.
  • Toughness: Resistance of a material to breakage from impact or sudden forces.

Physical Properties

  • Density: How compact a material is, calculated by mass divided by volume.
  • Melting Point: The temperature at which a solid turns into a liquid.
  • Electrical Conductivity: Ability to conduct electric current.
  • Thermal Conductivity: Ability to conduct heat.

Chemical Properties

  • Corrosion Resistance: Ability to resist degradation due to reaction with environmental elements.
  • Oxidation Resistance: Capacity to resist damage from exposure to oxygen.
  • Alkali Resistance: Resistance to damage caused by alkalis such as sodium hydroxide.
  • Acid Resistance: Ability to withstand exposure to different acids without deteriorating.