Cermets (ceramic–metal composites) combine high strength with high-temperature resistance. In which applications are cermets widely used due to these properties?

Introduction / Context:
Cermets are engineered composites of ceramic and metallic phases. They leverage ceramic hardness and thermal stability with metallic toughness and thermal shock tolerance, enabling service in extreme environments. Recognizing their typical application areas is foundational in materials selection.

Given Data / Assumptions:

• Properties: high-temperature capability, wear resistance, and sometimes oxidation resistance.
• Applications: high-performance, high-stress, or high-temperature environments.
• Comparison: conventional refractories vs advanced structural components.

Concept / Approach:

Cermets (e.g., TiC–Ni, WC–Co) are commonly used in aerospace (missile/spacecraft hot structures or guidance components), nuclear applications (control rod followers, some wear parts), and cutting tools. These are structural/functional components rather than mass thermal linings of large industrial furnaces, for which conventional refractories are more economical.

Step-by-Step Solution:

Verification / Alternative check:

Materials handbooks list cermets in cutting tools, rocket nozzles, and certain nuclear hardware, not as primary large-area refractory linings.

Why Other Options Are Wrong:

Hearth/roof/insulation of large furnaces: Typically lined with refractory bricks, castables, or fiber modules; cermets are unnecessary and uneconomical at scale.

Common Pitfalls:

Assuming superior properties imply universal usage; overlooking cost and fabrication constraints for large surfaces.

Final Answer:

Nuclear reactors, missiles, and spacecraft components