Top 10 Thermally Conductive Materials

Introduction

In advanced engineering, thermal conduction is essential for controlling heat in devices and machinery. Materials with high thermal conductivity transfer heat efficiently, improving performance and reliability. Below is a ranked guide to ten notable materials, starting with the most conductive.

1. Graphene (in-plane) (~5000 W/m·K, 3000°C)

Top of the list is graphene, a single molecule of carbon atoms. Its in-plane heat conductivity is suitable for microchips, flexible electronics, and proof-of-concept thermal systems. Currently in research stages, graphene has potential for substantial improvements in high-performance electronics.

2. Diamond (~2200 W/m·K, 2000°C)

Diamond possesses outstanding thermal conductivity alongside its hardness. Diamond is commonly used in high-performance cutting tools, laser heat spreaders, and aerospace heat sinks, where reliable performance in harsh environments is required.

3. Silver (~430 W/m·K)

Silver is the best metallic heat conductor. Utilised in printed circuit boards, thermal pastes, and heat exchangers, silver effectively transfers heat away from electronics but is costly for large-scale thermal applications.

4. Graphite (in-plane) (~400 W/m·K, 150°C)

Graphite provides excellent in-plane conductivity at a fraction of the cost of diamond or silver. The planar structure of graphite distributes heat effectively in batteries, lubricants, and electronic heat spreaders.

5. Hexagonal Boron Nitride (h-BN, in-plane) (~400 W/m·K, 250°C)

h-BN is unique in that it offers high thermal conductivity in addition to electrical insulativity. It is employed in high-temperature insulation, liquid cooling systems, and semiconductor packaging.

6. Copper (~400 W/m·K)

Copper represents a balance between cost and performance. Used for wiring, plumbing, and cooling applications, it serves as a general-purpose thermal conductor in both electrical and mechanical domains.

7. Silver-Diamond Composites (~1000 W/m·K, 600°C)

A composite of silver and diamond is engineered to achieve high conductivity and high-temperature operation. It is utilised in aerospace electronics and defence systems where both metal and diamond properties are required.

8. Silicon Carbide (SiC) (~270 W/m·K, 120°C)

SiC is recognised for its resistance to stress and thermal conductivity. It is applied in high-power electronics, ceramic components, and systems where heat resistance and longevity are necessary.

9. Aluminium (~205 W/m·K)

Aluminium is corrosion-resistant, lightweight, and straightforward to produce. Utilised in automotive, radiator, and consumer electronics applications, it provides adequate conductivity where weight is a consideration.

10. Aluminium Nitride (AlN) (~180 W/m·K, 140°C)

AlN provides excellent thermal conductivity along with electrical insulation, making it suitable for microelectronics, high-frequency circuits, and thin-thickness thermal management.

Summary Table

For more specific data and tech support, please check Stanford Advanced Materials (SAM).

Conclusion

From graphene's in-plane conductivity to aluminium nitride's combination of insulation with heat conduction, these materials fulfil a wide spectrum of engineering specifications. The selection of the appropriate material depends on the temperature range, electrical properties, cost, and specific performance requirements.

Frequently Asked Questions

F: Why does a material have thermal conductivity?

Q: Atomic bonding and structure affect the ability of a material to conduct heat.

F: How is high thermal conductivity used in electronics?

Q: It assists in dissipating excess heat, protects components, and maintains device operation.

F: Are these materials used under extreme temperature conditions?

Q: Yes, many perform sufficiently at high temperatures, ensuring reliability in demanding environments.