Tungsten has the highest melting point of all metals, 3422 degrees Celsius. This makes the material ideal for high temperature use in, for example, space rocket nozzles, high temperature furnace heaters or the fusion reactor. However, the metal is very brittle and therefore difficult to process. Researchers at the Karlsruhe Institute of Technology (KIT) have developed an innovative approach to make this brittle material flexible. To process tungsten, they determined new process parameters for electron beam fusion.
Tungsten is a metal with very attractive properties: it is corrosion resistant and as heavy as gold. In the form of tungsten carbide, it is as hard as diamond. And it has the highest melting point of any metal, 3,422 degrees Celsius. However, the metal is very brittle at room temperature. Due to its properties, tungsten is difficult to process with conventional methods. Treatment is expensive and time consuming. An alternative is 3D printing which makes it possible to produce tungsten components that require virtually no finishing. “Right now, we are working on additive manufacturing of tungsten components by electron beam fusion, abbreviated EBM,” says Dr. Steffen Antusch of the Institute for Applied Materials – Materials Science and Engineering (IAM-WK) of the KIT. The team succeeded in adapting the EBM process to tungsten. After developing specific process parameters, 3D printing of tungsten components is now possible. “This metal can be applied in many areas. Thanks to its special properties, it is ideally suited for high temperature applications in energy and light technologies, aerospace industry and medical engineering. It is indispensable in the modern high-tech industry, ”explains Alexander Klein, IAM-WK.
Preheating allows the treatment of fragile materials
EBM is an additive manufacturing method. The electrons accelerated under vacuum selectively melt the metal powder and thus produce a 3D component in an additive way, i.e. layer by layer. The big advantage of this method lies in the energy source used, the electron beam. It is used to preheat the metal powder and the backing plate before melting, which reduces the deformation and inherent stress. It is possible to process materials which break easily at room temperature and can deform at high temperature.
However, the materials used must be electrically conductive. Therefore, the process is not suitable for ceramic materials, because EBM is based on the principle of electric charge.
Lightweight titanium components for KA-RaceIning
Originally, EBM was developed to process titanium alloys and materials requiring higher processing temperatures. So far, EBM has been used to produce lightweight titanium components for KIT’s KA-RaceIng formula student project.
As part of the research programs of the Helmholtz Association and EUROfusion, the European fusion program, IAM-WK is studying materials and processes for future high temperature applications in fusion energy. or medical engineering. (rli)
Learn more about the KIT Materials Center: https://www.kit.edu/topics/materials.php
Contact for this press release
Regina Link, press officer, phone: +49 721 608-41158, e-mail: [email protected]
Being “the research university of the Helmholtz association”, KIT creates and transmits knowledge for society and the environment. The aim is to make significant contributions to global challenges in the fields of energy, mobility and information. For this, around 9,600 employees cooperate in a wide range of disciplines in natural sciences, engineering sciences, economics and human and social sciences. KIT prepares its 23,300 students for responsible tasks in society, industry and science by offering research-based study programs. KIT’s innovation efforts bridge important scientific discoveries and their application for the benefit of society, economic prosperity and the preservation of our natural basis of life. KIT is one of the German universities of excellence.
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