Composite Materials Quiz

Which of the following is NOT an example of a metal matrix composite (MMC)?

• Aluminum reinforced with silicon carbide (Al-SiC)

• Titanium reinforced with boron fibers

• Carbon fibers in an epoxy matrix

• Magnesium reinforced with ceramic particles

Answer explanation

Carbon fibers in an epoxy matrix is not a metal matrix composite (MMC) as it consists of a polymer matrix, while the other options involve metals reinforced with various materials.

Which closed mold fabrication method uses a vacuum to compact composite layers and reduce voids?

• Resin Transfer Molding (RTM)

• Compression Molding

• Vacuum Bag Molding

• Filament Winding

Answer explanation

Vacuum Bag Molding uses a vacuum to compress composite layers, effectively reducing voids and ensuring a denser final product. This method is specifically designed to enhance the quality of composite materials.

What is the primary advantage of structural composites like laminates or sandwich panels?

• High thermal conductivity

• Lightweight with excellent mechanical properties

• Easy to repair

• Cost-effectiveness

Answer explanation

The primary advantage of structural composites like laminates or sandwich panels is that they are lightweight while providing excellent mechanical properties, making them ideal for applications where strength-to-weight ratio is crucial.

Which type of matrix is commonly used in high-temperature components, such as engine parts and heat exchangers?

• Polymer matrix

• Metal matrix

• Ceramic matrix

• Hybrid matrix

Answer explanation

Metal matrix composites are preferred for high-temperature applications like engine parts and heat exchangers due to their excellent thermal stability and strength, making them suitable for extreme conditions.

What type of composite fabrication involves pulling resin-coated fibers through a heated die to form a cured composite?

• Pultrusion

• Hand Lay-Up

• Spray Lay-Up

• Hot Pressing

Answer explanation

Pultrusion is a composite fabrication process where resin-coated fibers are pulled through a heated die, curing the composite as it forms. This distinguishes it from other methods like Hand Lay-Up and Spray Lay-Up.

What are the two main components of a composite material?

• Polymer and ceramic

• Reinforcement and matrix

• Metal and fiber

• Thermoplastic and thermosetting

Answer explanation

The two main components of a composite material are the reinforcement and the matrix. The reinforcement provides strength and stiffness, while the matrix binds the reinforcement together and transfers loads.

Which of the following is a disadvantage of Polymer Matrix Composites (PMCs)?

• High thermal resistance

• High strength-to-weight ratio

• Limited performance in high-temperature environments

• Corrosion resistance

Answer explanation

Polymer Matrix Composites (PMCs) have limited performance in high-temperature environments, making them unsuitable for applications requiring high thermal stability, unlike metals or ceramics.

What is a characteristic of continuous fibers in composites?

• Provide isotropic properties

• Are distributed randomly within the matrix

• Provide high strength and stiffness in the fiber direction

• Enhance wear resistance

Answer explanation

Continuous fibers in composites provide high strength and stiffness primarily in the fiber direction, making them ideal for load-bearing applications. This characteristic enhances the overall performance of the composite material.

Which reinforcement type is typically used in brake pads and cutting tools?

• Continuous fibers

• Nanomaterials

• Particles

• Whiskers

Answer explanation

Particles are commonly used in brake pads and cutting tools due to their ability to enhance wear resistance and strength. They provide a good balance of performance and cost, making them ideal for these applications.

What is the main advantage of Ceramic Matrix Composites (CMCs)?

• Low production cost

• Exceptional thermal stability and resistance to high temperatures

• High ductility

• Easy machining

Answer explanation

The main advantage of Ceramic Matrix Composites (CMCs) is their exceptional thermal stability and resistance to high temperatures, making them ideal for applications in extreme environments.