3D printing of metals: New alloy enables printing of safe and reliable steel products

Steel alloys have already been used for additive manufacturing, but a new starting material in combination with the electron beam printing process now delivers a significantly higher quality in many respects, making its use sensible for the first time in many areas of application, says materials scientist Prof. Thomas Niendorf of the University of Kassel. His Emmy Noether research group, funded by the German Research Foundation, developed the alloy and the process together with colleagues from TU Bergakademie Freiberg. The results were published in the latest issue of the prestigious research journal Scientific Reports, an open access journal published by the Nature publishing group.

To develop their new material, the researchers took a previously untrodden path: they use as a basis a so-called TRIP steel alloy, which exhibits excellent stability due to special deformation mechanisms. They used the heat available in the electron beam printing process so skilfully that the unpredictability of the material properties, which has often been a problem up to now, is avoided. The result is a better internal material structure in the end product; this protects against unexpected fractures and other potential damage.

"Applications in aerospace and automotive, among others, current drivers behind the technological development of 3D printing, will benefit significantly from this. 3D metal printing will open up new areas on this basis," Prof. Niendorf is certain. He says the additive process is particularly suitable for complex, small components. Niendorf sees enormous potential for the German economy in metal 3D printing: "German manufacturers are leaders in the production of metal powders and the construction of equipment for 3D laser melting." Titanium alloys have dominated metal 3D printing worldwide to date. Unlike titanium products, steel components printed using the new process do not require extensive post-processing, making them much cheaper to produce.

In metal 3D printing, products are additively built up in micrometer-thin layers. To do this, metal powder is melted by an electron beam, laser or other heat source. This process makes it possible to create very delicate, complex and at the same time resilient structures. The search for new materials and processes suitable for 3D printing is one of the research focuses of Prof. Dr.-Ing. Thomas Niendorf. He has held a professorship for metallic materials at the University of Kassel since 2015. In the field of additive manufacturing, he conducts research on the manufacturing process and microstructure, mechanical properties and damage development of objects from the 3D printer.

Link to article: www.nature.com/articles/s41598-018-19376-0

Photos of Prof. Dr. Thomas Niendorf on request from the press office of the University of Kassel: presse@uni-kassel.de

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

Sebastian Mense
University of Kassel
Communication, Press and Public Relations
Tel.: +49 561 804-1961
E-Mail: presse[at]uni-kassel[dot]de
www.uni-kassel.de