In the recently published ‘Metal Filament 3D Printing of SS316L: Focusing on the Printing Process’, PhD student Karthikesh Gante Lokesha Renukaradhya examines additive manufacturing with metal for the machine design course in the Industrial Engineering and Management course at the Royal Institute of Technology. When analyzing previous studies, the author notices previous challenges and barriers such as cost and unavailability for all users.
Here the author focuses on a new AM technique that uses a metal-polymer composite filament to make a 316L stainless steel part on an FDM 3D printer. When using a Prusa 3D printer, two comparisons were offered, starting on the technical level with polymer techniques and then on the material level with stainless steel filaments.
The research also analyzed the following effects:
- Printing temperatures
- Nozzle types
- Print sample
- Adhesion between layers
Previous studies have shown that Fused Filament Fabrication (FFF, FDM) has great potential for manufacturing with metals and especially those with complex geometries:
“In addition, the FFF technology proves to be an advantage over other methods with regard to the simple and effortless change of materials. The tailor-made fused filament fabrication enables the effortless printing of green parts from 316L stainless steel raw material, but the surface properties achieved without post-treatment proved to be unsatisfactory for the surface-critical applications. A combination of green part printing and surface polishing in one printhead could possibly be room for further research, ”says the author.
While FDM 3D printing is popular for making with polymers, previous studies have shown that metal filaments are not that easy to come by and can also be costly. The researchers note that with the use of filler material and a significant increase in density, “both mechanical strength and production costs will increase proportionally”.
The samples were rated for printing parameters, with the samples showing better success when printed at 210 ° C instead of 235 ° C. The sample showed a “well packed structure” with no evidence of cracks. The geometric resolution was also good.
There were some debinding problems due to a rapid rise in temperature. The author found that slow and steady increases in temperature along with the use of supports and good airflow resulted in greater success.
“The main practical conclusion of this study was the results obtained with different printing parameters, structural integrity, which affects mechanical properties and geometric resolution. Another advantage of this developed FDM process is that the system enables an uncomplicated material change because, in contrast to the other AM techniques, which are time-consuming, only a new filament has to be inserted into the printhead, ”conclude the researchers.
“Debinding and sintering the sample was the hardest part and controlling all of the parameters added up to that challenge. After a series of trials, a number of parameters and equipment were selected, with minor parameter changes if necessary. It was also found that the rate of shrinkage from the green part of the final metal part varied in the x, y and z directions. Virtual foundry 316L stainless steel is an emerging and encouraging way to make metal parts for additive manufacturing, and there is always room for future research into this additive manufacturing area. “
Metal 3D printing has just continued to grow and has piqued interest not only from industrial users but also from many researchers as they conduct studies to eliminate porosity, combine traditional and new metal printing techniques, and make new superalloys. What do you think of this news? Let us know your thoughts! Join the discussion on this and other 3D printing topics on 3DPrintBoard.com.
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