Professor Thomas Niendorf in front of a 3D printer for metals. A special alloy now makes the production of printed steel products safe and reliable.
Andreas Fischer | Uni Kassel
According to a statement by the University of Kassel, one of its researchers has succeeded for the first time in having a steel alloy with an exceptionally high damage tolerance processed in a special 3D printer by means of "additive manufacturing". Printed products can therefore be produced more safely and reliably. Although steel alloys have already been used for additive manufacturing, “a new basic material in combination with the electron beam printing process now delivers a much higher quality in many respects and makes the use of these materials meaningful in many areas of application for the first time,” says materials scientist Professor Thomas Niendorf from the University of Kassel.
TRIP steel alloy
Niendorf's research group, which is funded under the Emmy Noether Programme and by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), has developed the alloy and the process together with colleagues from the TU Bergakademie Freiberg. The researchers chose an untried alternative method at the time, based on a so-called TRIP steel alloy, which demonstrates excellent stability due to its special deformation mechanisms.
The researchers used the heat available in the electron beam printing process so skilfully that the unpredictability of the material properties, which has often been problematic up to now, is avoided. The result is a better internal material structure in the end product; which protects against unexpected breaks and other possible damage.
The principle of 3D printing of metal
This technology has great potential for applications in aerospace and automotive technology. Niendorf is certain that "3D printing of metals on this basis will open up new areas". The additive process is particularly suitable for complex, small components. The researcher also sees tremendous opportunities for the German economy in 3D printing of metal: "German manufacturers are leaders in the production of metal powders and the construction of 3D laser melting systems."
Titanium alloys have up until now dominated worldwide 3D printing with metals. In contrast to these titanium products, steel components printed with the new process do not have to be reworked at great cost, which makes them much cheaper to produce. With 3D printing of metals, products are built up successively in micrometre-thin layers. For this purpose, metal powder is melted by an electron beam, laser or other heat sources. This process makes very delicate, complex, yet resilient structures possible.
The results were published in the latest issue of the scientific journal "Scientific Reports".