Advanced Composite Materials Quiz

Which of the following materials is known to fatigue?

• Aluminium

• Carbon fibre

• Nickel

• Epoxy resin

Answer explanation

Aluminium is known to fatigue due to its crystalline structure, which can develop microcracks under cyclic loading. In contrast, carbon fibre, nickel, and epoxy resin generally exhibit better fatigue resistance.

What is the commercial name for sheets of carbon fibre impregnated with resin?

• Prepreg

• Composite sheet

• Resin sheet

• Carbon laminate

Answer explanation

The correct answer is 'Prepreg', which refers to sheets of carbon fibre that are pre-impregnated with resin. This term is commonly used in the composites industry to describe this specific material.

What is a characteristic shared by both aluminium and carbon fibre composites?

• High ductility

• Brittleness

• Ability to be formed around curved surfaces

• High Young’s modulus

Answer explanation

Both aluminium and carbon fibre composites can be easily shaped and formed around curved surfaces, making them versatile for various applications. This characteristic is essential in industries like automotive and aerospace.

What is the purpose of an autoclave in the manufacturing of carbon fibre composites?

• To refrigerate the prepreg

• To cut the prepreg into sheets

• To press the prepreg into shape

• To cure the prepreg by heating

Answer explanation

The purpose of an autoclave in manufacturing carbon fibre composites is to cure the prepreg by heating. This process ensures that the resin in the prepreg hardens, providing the necessary strength and durability to the final composite.

What is the main difference between aluminium and carbon fibre in terms of deformation?

• Aluminium can be plastically deformed

• Carbon fibre can be plastically deformed

• Aluminium cannot be plastically deformed

• Carbon fibre is more ductile than aluminium

Answer explanation

Aluminium can undergo plastic deformation, meaning it can be permanently shaped without breaking. In contrast, carbon fibre is more brittle and does not exhibit plastic deformation, making aluminium the correct choice.

Which property makes carbon fibre composites preferable for aerospace applications over aluminium?

• Higher strength-to-weight ratio

• Greater electrical conductivity

• Lower thermal conductivity

• Higher density

Answer explanation

Carbon fibre composites have a higher strength-to-weight ratio than aluminium, making them lighter and stronger, which is crucial for aerospace applications where weight savings are essential for performance.

Which of the following is a disadvantage of using carbon fibre composites?

• Low strength

• High cost

• High weight

• Low corrosion resistance

Answer explanation

The correct choice is 'High cost' because carbon fibre composites are expensive to produce, which can limit their use despite their advantages in strength and weight.

What is a common application of carbon fibre composites in the automotive industry?

• Body panels

• Exhaust systems

• Fuel tanks

• Engine blocks

Answer explanation

Carbon fibre composites are commonly used for body panels in the automotive industry due to their lightweight and high strength, which improve fuel efficiency and performance. Other options like exhaust systems and engine blocks typically use metals.

Which process is used to enhance the strength of aluminium alloys?

• Annealing

• Quenching

• Tempering

• Age hardening

Answer explanation

Age hardening, also known as precipitation hardening, is a heat treatment process specifically used to enhance the strength of aluminium alloys by promoting the formation of fine precipitates that impede dislocation movement.

What is a key environmental concern associated with the production of carbon fibre composites?

• High energy consumption

• Soil erosion

• Water pollution

• Deforestation

Answer explanation

The production of carbon fibre composites is energy-intensive, leading to high energy consumption, which is a significant environmental concern. This process requires substantial electricity, contributing to carbon emissions.