Alloys

• What is the definition of an alloy?


  An alloy contains a metal blended with other elements.
• Why are alloys generally harder than pure metals?


  Alloys have atoms of different sizes that disrupt the layers, preventing them from sliding.
• What are the properties of alloys compared to pure metals?


  • Alloys tend to be harder than pure metals.
  • Alloys do not slide over each other as easily as pure metals.
• What are the components of bronze?


  Bronze is an alloy of copper and tin.
• Why is bronze used for statues?


  Because bronze is extremely hard and tends not to corrode.
• What are the components of brass?


  Brass is an alloy of copper and zinc.
• What are the uses of brass?


  Brass is used for musical instruments and door handles.
• Why is pure gold usually alloyed with other metals?


  Pure gold is too soft, so it is alloyed to make it harder.
• What metals are commonly used to alloy with gold?


  Gold is alloyed with silver, copper, and zinc.
• How is the purity of gold rated?

  The purity of gold is rated in carats.
• What is the carat rating of 100% pure gold?


  24 karat is 100% pure gold.
• What is the carat rating of 75% gold?


  18 karat is 75% gold.
• What is steel?


  Steel is an alloy of iron containing specific amounts of carbon.
• What is the difference between high carbon steel and low carbon steel?


  High carbon steel is extremely hard but brittle, while low carbon steel is softer and more easily shaped.
• What is high carbon steel used for?


  High carbon steel is used to make cutting tools such as chisels.
• What is low carbon steel used for?


  Low carbon steel is used to make car bodies.
• What is the problem with steel, and how is it addressed?


  Steel can rust, so stainless steel contains chromium and nickel to prevent corrosion.
• What is stainless steel?


  Stainless steel is hard and resistant to corrosion, containing chromium and nickel.
• What are aluminium alloys known for?


  Aluminium alloys are known for their low density.
• Why are aluminium alloys useful in aeroplane bodies?


  Because aluminium alloys are low density, making them lightweight.
• What are the uses of different forms of steel?

  • High carbon steel: used for cutting tools (e.g., chisels)
  • Low carbon steel: used for car bodies
  • Stainless steel: used for items requiring corrosion resistance
• What are the main alloys discussed in the material?


  • Bronze: copper and tin
  • Brass: copper and zinc
  • Gold alloys: gold with silver, copper, and zinc
  • Steel: iron and carbon
  • Stainless steel: iron, carbon, chromium, and nickel
  • Aluminium alloys: aluminium with other elements