Thermally Conductive is a measure of a material’s ability to transfer heat. Materials with high thermal conductivity can transfer heat efficiently and easily absorb heat from the environment. A bad heat conductor obstructs heat flow and slowly draws heat from the surrounding area. According to the S.I (International Systems) Guidelines, the thermal conductivity of materials is measured in watts per meter per Kelvin (W/m•K).
Key words
materials with the highest thermal conductivity
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Natural heat-conducting material.The first 10 thermal conductivity materials measured and their values are summarized below. Since the variation in thermal conductivity depends on the equipment used and the environment in which the measurements were obtained, these conductivity values are averages.
1. Diamond — 2000 — 2200 W/m•K
Diamond is nature’s best heat-conducting material, and its conductivity is measured 5 times higher than that of copper, the most manufactured metal in the United States. Diamond atom consists of a simple carbon skeleton, which is an ideal molecular structure for efficient heat transfer. In general, materials with the simplest chemical composition and molecular structure have the highest thermal conductivity values. Diamonds are an important component of many modern handheld electronic devices. Their role in electronics is to promote heat dissipation and protect sensitive computer components. The high thermal conductivity of diamonds has also proved useful when determining the authenticity of gemstones in jewellery. Adding a small amount of diamond to tools and techniques can have a dramatic effect on thermal conductivity.
2. Silver — 429 W/m•K
Silver is a relatively inexpensive and abundant heat conductor. Silver is a component of many electrical appliances and is one of the most widely used metals because of its malleability. Thirty-five percent of silver made in the United States is used in power tools and electronics (US Geological Survey Mineral Communities 2013). Demand for silver pulp, a by-product of silver, has increased as it is used as an environmentally friendly energy alternative. The silver paste is used to make photovoltaic cells, the main component of solar panels.
3. Copper – 398 W/m•K
Copper is the most commonly used metal in the manufacture of conductive appliances in the United States. Copper has a high melting point and moderate corrosion rate. It is also a very efficient metal that minimizes energy loss during heat transfer. Metal POTS, hot water pipes and car radiators are all appliances that take advantage of copper’s conductive properties.
4. Gold — 315 W/m•K
Gold is a rare and expensive metal used in specific conductive applications. Unlike silver and copper, gold rarely changes color and can withstand a lot of corrosive conditions.
5. Aluminum nitride — 310 W/m•K
Aluminum nitride is often used as a substitute for beryllium oxide. Unlike beryllium oxide, aluminum nitride does not pose a manufacturing health hazard, but still displays similar chemical and physical properties to beryllium oxide. Aluminum nitride is one of the few materials with high thermal conductivity and electrical insulation. It has remarkable thermal shock resistance and acts as an electrical insulator in mechanical chips.
6. Silicon Carbide — 270 W/m•K
Silicon carbide is a semiconductor consisting of a balanced mixture of silicon and carbon atoms. When made and fused together, silicon and carbon combine to form an extremely hard and durable material. This mixture is commonly used as a component of car brakes, turbines and steel mixtures.
7. Aluminum — 247 W/m•K
Aluminum is commonly used as a cost-effective alternative to copper. Although not as conductive as copper, aluminum is abundant and easy to handle because of its low melting point. Aluminum is currently the main material for cooling all electronic components. There are profile heat sink, die casting process heat sink and so on.
8. Tungsten — 173 W/m•K
Tungsten has a high melting point and low vapor pressure, making it an ideal material for electrical appliances exposed to high levels of power. Tungsten’s chemical inertness allows it to be used as an electrode as part of an electron microscope without changing the current. It is also often used in light bulbs and cathode ray tube components.
9. Graphite 168 W/m•K
Graphite is a resource-rich, low-cost and lightweight alternative to other carbon allotropes. It is often used as an additive in polymer mixtures to enhance their thermal conductivity. Batteries are a common example of electrical appliances that use graphite for high thermal conductivity.
10. Zinc 116 W/m•K
Zinc is one of the few metals that can be easily combined with other metals to form metal alloys (mixtures of two or more metals). Twenty percent of all zinc appliances in the United States are made of zinc alloys. Galvanizing uses 40% pure zinc to make. Galvanizing is the process of applying a zinc coating to steel or iron, designed to protect the metal from weathering and rust.
