Properties of Alloys and Aluminium

Evaluate the reasons for using non-ferrous metals in the construction of aircraft.

• They are cheaper than ferrous metals.

• They offer a high strength-to-weight ratio, are corrosion-resistant, and allow for fuel efficiency and higher performance.

• They are easier to work with than ferrous metals.

• They are more readily available than ferrous metals.

Evaluate the choice of materials used in the fuselage of an aircraft.

• Aluminium alloys are used for their lightweight nature and corrosion resistance.

• Steel is commonly used due to its low cost and availability.

• Plastic composites are preferred for their flexibility and ease of manufacturing.

• Copper is used for its electrical conductivity and weight.

Explain how the properties of aluminium make it suitable for its application in aircraft fuselages.

• Aluminium is a heavy metal that provides strength to aircraft fuselages.

• Aluminium has a low density, high corrosion resistance, and good formability for complex shapes.

• Aluminium is a poor conductor of heat, making it unsuitable for aircraft fuselages.

• Aluminium requires extensive protective coatings to prevent corrosion in aircraft fuselages.

What is an alloy?

• A pure metal with no other elements.

• A mixture of a metal with other elements that improves strength, hardness, or corrosion resistance.

• A type of metal that is used in jewelry making.

• A chemical compound formed by two or more metals.

Why is copper used in electrical systems?

• It is a cheap metal that is widely available.

• It has excellent electrical conductivity and is ductile, making it easy to form into wires.

• It is resistant to corrosion and does not oxidize easily.

• It has a low melting point, making it easy to work with.

Explain why engineers select non-ferrous metals for applications in the civil structures or transport industries.

• Non-ferrous metals are cheaper than ferrous metals.

• Non-ferrous metals are heavier and stronger than ferrous metals.

• Engineers select non-ferrous metals such as aluminium, copper, and titanium due to their distinct properties.

• Non-ferrous metals are more readily available than ferrous metals.

Name one ferrous and one non-ferrous metal used in engineering products. Describe an application of each.

• Ferrous metal: Aluminum — used in aircraft manufacturing due to its lightweight properties. Non-ferrous metal: Copper — used in electrical wiring because of its high electrical conductivity and ductility.

• Ferrous metal: Mild steel — used in construction beams due to its strength and availability. Non-ferrous metal: Lead — used in batteries because of its ability to store energy.

• Ferrous metal: Cast iron — used in cookware due to its heat retention. Non-ferrous metal: Brass — used in musical instruments for its acoustic properties.

• Ferrous metal: Stainless steel — used in kitchen appliances for its corrosion resistance. Non-ferrous metal: Gold — used in electronics for its conductivity.

Why are epoxy primers used on high-strength aluminium alloys like 7075?

• They enhance the aesthetic appearance of the metal.

• They act as a barrier coating that protects against moisture and environmental damage.

• They improve the electrical conductivity of the alloy.

• They increase the weight of the aircraft components.

Compare the use of aluminium alloys and ferrous metals in transport structures.

• Aluminium alloys are lighter and resist corrosion better than ferrous metals, making them ideal for vehicles and aircraft.

• Ferrous metals are lighter and more resistant to corrosion than aluminium alloys, making them ideal for vehicles.

• Aluminium alloys are stronger and less expensive than ferrous metals, making them ideal for transport structures.

• Ferrous metals are lighter and more cost-effective than aluminium alloys, making them suitable for aircraft.

What is quenching and why is it important?

• Quenching is the rapid cooling of the heated alloy, which traps the dissolved alloying elements in place before they can form large particles.

• Quenching is the process of slowly heating an alloy to allow for the formation of large particles.

• Quenching involves mixing different alloys to create a new material with unique properties.

• Quenching is the removal of impurities from an alloy to enhance its strength.