Question

Evaluate the potential benefits and drawbacks of using ceramic matrix composites (CMCs) in aerospace engine components.

• A. Benefits include lower weight and higher temperature tolerance; drawbacks include higher costs and complexity in manufacturing.
• B. Benefits include higher electrical conductivity; drawbacks include lower thermal stability.
• C. Benefits include easier processing; drawbacks include higher material costs only.
• D. Benefits include increased thermal conductivity; drawbacks include reduced mechanical strength.

Hint:

Ceramic Matrix Composites (CMCs). Advantages: High-temperature strength, Low density (weight saving), Good wear/corrosion resistance. Disadvantages: High cost, Complex manufacturing, Relatively brittle behavior (compared to metals). Used in demanding applications (aerospace engines, thermal protection).

Answer 1

The Correct Option is A

Ceramic Matrix Composites (CMCs), such as carbon fibers or silicon carbide fibers embedded in a ceramic matrix (e.
g.
, silicon carbide), are advanced materials considered for high-temperature applications like aerospace engine hot sections (turbines, combustors).
- Benefits: Compared to traditional metal superalloys, CMCs offer significantly lower density (lower weight, crucial for aerospace) and can withstand much higher operating temperatures without significant degradation or need for extensive cooling.
This allows engines to run hotter and more efficiently.
(Lower weight, higher temperature tolerance).
- Drawbacks: The manufacturing processes for CMCs are complex and expensive.
They are also inherently less ductile than metals, although much tougher than monolithic ceramics, making design and damage tolerance critical considerations.
(Higher costs, manufacturing complexity).
Option (1) correctly summarizes the key benefits (low weight, high temp capability) and drawbacks (cost, manufacturing complexity).
Option (2) is incorrect (CMCs are generally insulators).
Option (3) is incorrect (processing is difficult).
Option (4) is incorrect (CMCs have relatively low thermal conductivity compared to metals, and their key advantage is high-temperature strength).