Top 10 Materials with the Highest Thermal Conductivity for Heat Dissipation
Thermal conductivity refers to a material's ability to transfer heat. Materials with high thermal conductivity can effectively transfer heat and absorb it quickly from their surroundings. Poor thermal conductors, on the other hand, hinder heat flow and absorb heat at a slower rate. According to the International System of Units (SI), thermal conductivity is measured in watts per meter per kelvin (W/m·K). The following list outlines the top 10 materials with the highest thermal conductivity values, based on average measurements.
Natural Heat-Conducting Materials
1.Diamond – 2000-2200 W/m·K
Diamond is the best natural heat conductor, with a thermal conductivity value five times higher than copper, one of the most commonly used metals in manufacturing. Diamond's atomic structure, composed of a simple carbon lattice, makes it an ideal material for efficient heat transfer. Its use in modern handheld electronics helps dissipate heat and protect sensitive components. Additionally, diamond's high thermal conductivity is useful in determining the authenticity of gemstones.
2.Silver – 429 W/m·K
Silver is a relatively affordable and abundant heat conductor, widely used in electrical devices. Due to its malleability, silver is one of the most versatile metals, and about 35% of silver produced in the U.S. is used in electrical tools and electronic products. Additionally, silver paste is in high demand for its use in photovoltaic cells, a key component in solar panels.
3.Copper – 398 W/m·K
Copper is one of the most commonly used metals in electrical and heat-conductive applications. With its high melting point and medium corrosion rate, copper minimizes energy loss during heat transfer. It is used in various devices such as metal pots, water pipes, and car radiators.
4.Gold – 315 W/m·K
Gold is a rare and expensive metal used for specific conductive applications. Unlike silver and copper, gold is resistant to tarnishing and can withstand corrosive conditions. It is often used in electronics where corrosion resistance is critical.
5.Aluminum Nitride – 310 W/m·K
Aluminum nitride is often used as a substitute for beryllium oxide due to its similar thermal and physical properties, but without the health hazards associated with beryllium. It is one of the few materials that combine high thermal conductivity with electrical insulation, and it plays a crucial role in electronic devices as an insulator with exceptional thermal shock resistance.
6.Silicon Carbide – 270 W/m·K
Silicon carbide, a semiconductor composed of silicon and carbon atoms, forms a highly durable material when fused. Silicon carbide is widely used in automotive brake systems, turbines, and steel mixtures for its hardness and resistance to wear.
7.Aluminum – 247 W/m·K
Aluminum is often used as a cost-effective substitute for copper in heat-conductive applications. While it is not as conductive as copper, aluminum is abundant, easy to handle, and has a lower melting point. It is an essential component in LED lighting and is increasingly used in copper-aluminum alloy mixtures.
8.Tungsten – 173 W/m·K
Tungsten, with its high melting point and low vapor pressure, is ideal for devices exposed to high-power electrical currents. Its chemical inertness allows it to be used as an electrode in electron microscopes without altering the current. Tungsten is also used in light bulbs and cathode ray tubes.
9.Graphite – 168 W/m·K
Graphite, a resource-rich, low-cost, and lightweight form of carbon, is often used as an additive in polymer mixtures to enhance their thermal conductivity. Batteries are one of the most common devices utilizing graphite’s high thermal conductivity.
10.Zinc – 116 W/m·K
Zinc is one of the few metals that easily combine with other metals to form alloys. About 20% of zinc in the U.S. is used to make zinc alloys. Galvanization, the process of coating steel or iron with a layer of zinc, helps protect the metal from weathering and rust.
Engineered Surface-Coating Materials
1.DLC Diamond-Like Carbon Coating
Manufactured through vacuum deposition technology and PVD (Physical Vapor Deposition) processes, DLC coatings offer excellent thermal conductivity and insulation properties. These coatings are used in a wide range of applications where both thermal and electrical insulation are needed.
2.Aluminum Oxide (Al2O3) Coating
Produced using CVD (Chemical Vapor Deposition), aluminum oxide coatings are commonly used in applications requiring both insulation and good thermal conductivity. While these coatings offer superior control over film thickness and adhesion compared to thermal spraying, their high cost limits widespread adoption. Thermal conductivity: 23-32 W/m·K.
3.Hexagonal Boron Nitride (HBN) Coating
HBN coatings, with a thermal conductivity of 33 W/m·K, are the best ceramic coatings for high-temperature applications above 500°C. HBN is also an excellent ceramic insulator with a breakdown voltage of 3 kV/mm. It is chemically inert and can withstand oxidation in oxygen at temperatures up to 900°C and in an oxygen-free environment up to 2000°C.
4.Beryllium Oxide (BeO) Coating
Beryllium oxide has thermal conductivity similar to that of copper and is used in high-performance heat dissipation applications. However, the powder form is toxic, and BeO starts to volatilize at temperatures above 1000°C. As a result, it is gradually being phased out in favor of safer alternatives.