Alloys and their Properties | Chemistry for Grade 11 (IGCSE) PDF Download

Properties & Uses of Alloys

• Alloys are mixtures of two or more metals or a metal with a non-metal like carbon.
• Alloys often exhibit unique properties distinct from the metals they are composed of, such as increased strength, hardness, and resistance to corrosion or extreme temperatures.
• These enhanced characteristics can render alloys more practical than pure metals.

Common Alloys and Their Uses

• Alloys are mixtures of metals that exhibit enhanced properties compared to their individual components. They are not chemically combined like compounds.
• Brass is an alloy of copper and zinc, known for its superior strength compared to the individual metals.
  • Utilized in crafting musical instruments, ornamental pieces, and door knobs due to its durability.
• Stainless steel comprises iron along with elements like chromium, nickel, and carbon. It is valued for its toughness and resistance to rust.
  • Commonly employed in the production of cutlery owing to its hardness and anti-corrosive properties.
• Alloys of iron, when combined with elements like tungsten, chromium, or nickel, exhibit specialized properties.
  • Iron alloys with tungsten are renowned for their extreme hardness and ability to withstand high temperatures.
  • Alloys incorporating chromium or nickel are known for their corrosion resistance.
• Aluminium alloys are created by blending aluminium with metals like copper, manganese, and silicon to enhance strength while maintaining low density.

Explaining the Properties of Alloys

• Alloys are composed of atoms of varying sizes, leading to a distortion of the typically regular atomic arrangements found in pure metals. This distortion significantly impacts the properties of alloys.
• This distortion effect plays a crucial role in increasing the hardness of alloys compared to pure metals. It hinders the smooth sliding of atomic layers over each other, making the material stronger and more resistant to deformation.