Properties of Alloys and Aluminium

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

• Non-ferrous metals are cheaper than ferrous metals.

• Non-ferrous metals like aluminium and titanium offer a high strength-to-weight ratio, are corrosion-resistant, and allow for fuel efficiency and higher performance.

• Non-ferrous metals are heavier and more durable than ferrous metals.

• Non-ferrous metals are easier to weld and shape than ferrous metals.

What is Aluminium Alloy 2024 used for, and what are its key alloying elements?

• Used in marine applications due to its high corrosion resistance.

• Used in aircraft fuselages and structural components due to its high strength and fatigue resistance.

• Used in automotive parts for its lightweight properties.

• Used in electrical wiring because of its conductivity.

What makes an aluminium alloy suitable for precipitation hardening?

• The alloy must contain the right elements like copper, magnesium, or zinc.

• The alloy must be pure aluminium without any alloying elements.

• The alloy must be heated to a temperature above 1000°C.

• The alloy must have a high carbon content.

Why is aluminium used in the manufacture of aircraft fuselages?

• It is the cheapest metal available.

• It has a high strength-to-weight ratio, making it ideal for aerospace structures where weight savings are critical.

• It is highly resistant to corrosion and does not require painting.

• It is a good conductor of electricity, which is essential for aircraft systems.

What is Alclad and why is it used with aluminium alloys like 7075 and 2024?

• A thin layer of pure aluminium bonded to a high-strength core alloy that improves corrosion resistance.

• A type of aluminium alloy that is stronger than 7075 and 2024.

• A coating that reduces the weight of aluminium alloys significantly.

• A method of welding aluminium alloys together.

What is ageing in precipitation hardening?

• A process involving cooling the alloy at a high temperature

• A method of reheating the quenched alloy at a lower temperature for a long time

• A technique that involves rapid cooling of the alloy

• A procedure that eliminates all second-phase particles from the alloy

Discuss the selection of materials used in the construction of aircraft, including a comparison of ferrous and non-ferrous metals.

• Ferrous metals are lighter and more corrosion-resistant than non-ferrous metals.

• Non-ferrous metals like aluminium and titanium are lighter and more corrosion-resistant, making them preferred in aerospace.

• Ferrous metals are always preferred in aerospace due to their strength.

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

What are the alloying elements in Aluminium Alloy 7075?

• Zinc (Zn), Magnesium (Mg), Copper (Cu)

• Aluminium (Al), Silicon (Si), Iron (Fe)

• Nickel (Ni), Titanium (Ti), Manganese (Mn)

• Lead (Pb), Bismuth (Bi), Tin (Sn)

What are the alloying elements in Aluminium Alloy 6061 and where is it used?

• Copper (Cu) and Zinc (Zn)

• Magnesium (Mg) and Silicon (Si)

• Iron (Fe) and Manganese (Mn)

• Nickel (Ni) and Titanium (Ti)

What is the Hall–Petch relationship?

• The Hall–Petch relationship states that as grain size increases, the strength of a metal increases.

• The Hall–Petch relationship explains that as grain size decreases, the strength of a metal increases.

• The Hall–Petch relationship indicates that grain size has no effect on the strength of a metal.

• The Hall–Petch relationship suggests that finer grains lead to more ductility in metals.