On July 5, 2019, researchers at the Graz University of Technology (TU Graz) in Austria modified 316L stainless steel powder to achieve better print quality and surface finish when used in additive manufacturing.
It is reported that the groundbreaking aspect of this research is to add silicon nitride to 316L stainless steel to control the reaction of boride, which is used as an activator during the sintering process. Using this method, researchers were able to minimize the need for support structures and produce parts with better surface and mechanical properties.
According to co-author Mateusz Skalon of the research paper, this modified powder, called NewGen SLM powder, "can save 3D printed metal costs by up to 114 euros / kg."
NewGen SLM Metal 3D Printing Powder
3D printing of metals allows the creation of highly complex and lightweight end-use parts that can be used in the aerospace industry or biomedicine. However, despite the need for metal 3D printing, there are still challenges to overcome, such as minimizing support structures and improving the surface quality of finished parts.
NewGen SLM is made using boride, which is mixed with 316L stainless steel powder. Although borides increase the density of the sinter, they do not dissolve well in iron-based materials, and they form a layer around the particles after melting and solidifying. To control the behavior of the boride to obtain the desired result, silicon nitride is added to the metal powder.
Researchers tested the physical and mechanical properties and porosity of 20 different laboratory-made 316L stainless steel powder blends. The conclusion is that the deformation of the sintered body can be reduced by controlling the amounts of silicon nitride and boron.
The author wrote: "By adding different proportions of boron and Si3 N4 to AISI 316L stainless steel, the deformation and lateral fracture strength of the sintered ore can be controlled by directly controlling the solidified second phase (amount from the eutectic)."
In addition, TU Graz scientists have modified the powder. In addition to producing better surface finish and mechanical properties, NewGen SLM also requires fewer support structures.
Commercialization of NewGen SLM
With the support of TU Graz, the researchers intend to commercialize the NewGen SLM powder.
Skalon said: "We will test the powder on the most common laser melting system within the next 16 months. Based on this, we hope to establish a production company directly in Austria after Fellowship. The 316L stainless steel powder purchased will be modified and sold . "
"The target group will include manufacturers of highly complex metal parts, companies that make cars, aircraft and mechanical engineering departments, and research institutions that use additive manufacturing."