Metals are made up of atoms that are composed of electrons held in orbit by the pull of the nucleus. When exposed to light, metals give off energy, this phenomenon is referred to as the photoelectric effect. The light has to be of a certain frequency for this to be effective. This means that the energy required to pull the electrons from the atom of the metal must exceed the force exerted by the nucleus on the metal.
The total amount of force or energy required to achieve this (i.e., take an electron out of metal) is referred to as the Work Function of that meta. In this article, we will focus on the work function of different metals such as Molybdenum metal, Hafnium, Titanium, etc., as well as the importance of work function.
Every metal has a specific work function. The work function of a metal is the minimum amount of energy that will take out an electron from the orbital of an atom. The value of the work function is equal to the energy of the electron revolving around the nucleus. It is measured in electron volt (eV)
When metals are heated, they give off electrons in the form of energy. Work function is important in studying the thermionic emission of metals. As temperatures of metals increase when heated, the electrons on the surface of the metal gain energy and this energy makes them move a short distance off the surface of the metal causing emission of electrons. This is known as thermionic emission, and it is important in understanding how X-ray tubes work.
Certain metals are used as filaments; an example is a pure Tungsten. The filaments must be heated to a certain temperature of 3,992°F (2,200°C) before a useful number of electrons can be emitted for the x-ray study. The study of Work Function helps us identify the temperature at which refractory metals can be heated before thermionic emission will occur. This helps in equipment design and specification.
Copper is a reddish substance that is soft, malleable, and ductile. It is the earliest metal used by man and remains one of the most important metals used in the industry. It ranks as the third most used metal in the world just behind Iron and Aluminum. It is used extensively in making electrical wires, telecommunication cables, and in making electronic products. Copper has a melting point of 1,984.32°F (1,084.62°C) and a high electrical conductance second only to silver. The work function of copper is 4.53 – 5.10 eV.
Molybdenum is a widely used refractory metal. It provides good mechanical properties even at very high temperatures. It has low thermal expansion and high thermal conductivity and is used in making bearing parts, elevator brakes, furnace parts, and forging dyes. Molybdenum has a melting point of 4,753°F (2,623°C) and is used in making glass melting solids due to its high electrical conductivity. The work function of Molybdenum is 4.36 – 4.95 eV.
Steel is basically an alloy of iron and carbon. It is used as a material in most engineering and construction works due to its high tensile strength and low cost. Steels do not corrode easily and have very good ductility, too. The work function of steel is 4.4 eV.
Hafnium is a ductile metal with a brilliant silvery luster. Hafnium is used in fabricating nuclear-control rods. It is highly resistant to corrosion and acids. It has a high melting point of 4,041°F (2,227°C). This very high temperature makes it ideal for use as a refractory material, similar to molybdenum. The work function of Hafnium is 3.90 eV.
Titanium is a silvery-gray metal, it is known for its lightweight, low corrosion, and high strength. Due to its high strength and low density, it is used as an alloy in making the different parts of a high-speed aircraft. Titanium has a melting point of 3,034.4°F (1,668°C) centigrade. It has a work function of 4.33 eV.
Tungsten is a strong refractory metal used as lamp filaments and also to increase the hardness and strength of steel. It has a melting point of 6,191.6°F (3,422°C). The metal is resistant to chemical attack and maintains high tensile strength even at very high temperatures. The work function of Tungsten is 4.32 – 5.22 eV.
Zinc is a low melting metal with very high commercial importance. It has a relatively low melting point of 773.6°F (420°C). Oxides of zinc are used as a semiconductor. Zinc is also used in the cosmetics, plastics, and pharmaceutical industries. The work function of Zinc is 3.63 – 4.9 eV.
Aluminum is the most abundant metal on the earth’s crust. It is very lightweight and has a low melting point of 1,236.2°F (669°C). Aluminum is added to several other metals to improve their properties. The metal and its alloys are used in the construction of aircraft, electrical conductors, chemical equipment, etc. Aluminum is highly malleable and durable, and highly resistant to corrosion. The Work function of Aluminum is 4.06 – 4.26 eV.
Refractory metals have wide applications in areas where materials of construction should not be deformed or affected by high temperatures. At Advanced Recovery Metals, we provide high-quality refractory metals that meet all industrial applications. Our wires, plate, sheets, and rods made from quality Molybdenum metals, such as Tungsten and Titanium are made with the highest standards in the USA. For further inquiries, call us at (949) 407-8904 and speak to any of our professionals.
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