Electron beam 3D printer for metals at the University of Kassel

In the 3D printer at the University of Kassel, metal powder is melted by an electron beam. Such systems are still rare at German universities. They are used primarily in the high-tech sector. Since the process has not yet been sufficiently tested for all branches of industry, it is constantly being further developed. This is where the researchers from Kassel are doing fundamental work - for example, when it comes to adapting the physical properties of the finished products to the needs of the various industries. The printer at the University of Kassel, worth around 750,000 euros, was 100 percent funded by the DFG.

To print an object, the Kassel engineers must first make a virtual model of the object and translate the data on the computer for the printer. Each layer that the printer applies is only about 30 to 150 micrometers thick - roughly the diameter of a human hair. Depending on the size of the individual parts, a large number of different objects can be produced simultaneously in one printing process. During the printing process, the temperature inside the printer is up to 1200 degrees Celsius. After printing, all parts are freed from surrounding metal powder, post-treated and tested.

Titanium alloys dominate metal 3D printing worldwide. They account for about 80 percent of the global market. They are certified for the biomedical and aerospace industries, among others. In addition to searching for other suitable metals, the engineers at the University of Kassel are conducting research primarily in the area of post-processing and testing of the printed products. Niendorf emphasizes, "We test every part that leaves the printer for stability and condition. We have various X-ray diffractometers, two scanning electromicroscopes, mechanical testing machines and a computer tomograph at our disposal for this purpose."

Opportunities for the German economy

Since October 2015, Dr.-Ing. Thomas Niendorf has been a professor in the Metallic Materials Department of the Institute of Materials Engineering. Niendorf is an expert in 3D printing with metals and focuses his research on the manufacturing process and microstructure, mechanical properties and damage development of objects from the 3D printer. Niendorf studied and earned his doctorate at the University of Paderborn. From 2010 to 2014, he headed the area of material fatigue there. He then spent about a year conducting research at the TU Bergakademie Freiberg.

The market for 3D printing with metals has grown strongly in the last five years. Niendorf explains, "The objects we produce are extremely delicate and complex. You often couldn't produce them any other way than 3D printing." The scientist does not expect a loss of jobs for the German economy as a result of the new type of production: "German manufacturers are leaders in the production of metal powders and the construction of equipment for 3D laser melting." In addition, many companies showed interest in experts for 3D printing. Accordingly, he said, the need for skilled workers is great.

The University of Kassel is a young, modern university with around 330 professors and about 24,000 students. One of its research focuses is materials and production engineering.

Photoof Prof. Niendorf (Photo: Uni Kassel) for download at: http://www.uni-kassel.de/uni/fileadmin/datas/uni/presse/anhaenge/2016/Prof._Dr.-Ing._Thomas_Niendorf_3D_Drucker.jpg

Caption: Prof. Dr.-Ing Thomas Niendorf prepares the next printing process at the 3D printer for metals. Together with his team, he is working on optimizing the printing process to build as error-free as possible.

Contact:

Prof. Dr.-Ing Thomas Niendorf
University of Kassel
Institute of Materials Engineering
Department of Metallic Materials
Tel.: 0561 804 7018
E-mail: niendorf[at]uni-kassel[dot]de
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