Project Description: I conducted this investigation as my primary project for my Summer 2023 internship at Parker Hannifin. My manager was aware of BASF Ultrafuse filament, which is polymer filled with metal particles that can be printed and then sintered into solid metal parts. They tasked me with experimenting with a spool of this material to determine if it could be a viable, low-cost option for Parker manufacturing sites to add metal 3D printing to their capabilities. I developed a series of test prints to explore the limitations of this material. I then wrote up a white-paper-esque report of my results including suggestions and cost comparisons to other metal 3D printing options.
Big Wins: I was able to identify strengths and weaknesses of this material compared to traditional (orders of magnitude more expensive) metal 3D printing techniques. After writing the report, I identified real Parker parts that were a good candidate to further test and evaluate this option. This was a nice preparatory project focused on experimental design as I started grad school right afterwards.
Challenges: This material was challenging to work with. It had poor adhesion for layers and walls, and low green-part strength due to dense metal loading. Final parts also shrunk considerably and were prone to cracking during sintering. The MakerBot slicing options were also more restrictive than I was used to, which created problems and weird behavior at times.
Key Takeaways: Metal FDM is a low-budget option for metal parts for future projects, but the sintering lead time has to be worked around. Start working on longer reports and documents early and chip away at it over time.
Here are the test objects that I printed for this experiment. The back row is complex parts acting as stress tests for the process. The cubes and capped cylinders in front of that were to look at print parameters and infill effects. The two sets of gears for the bottom rows were to test functional printing capabilities.
Here are the parts as I received them after shipping. The pyramid collapsed. I was attempting to recreate a stress test from the marketing material with that object, but I failed to realize that the arms slightly tapered so that the tip was lighter that mine ended up. The Benchy also failed spectacularly. The rest of the parts came out well for the most part.
I was able to tap threads into the cradle for this little gear toy I modeled, and the gears run pretty well. Some of the teeth delaminated from the bed, creating a bulge that can occasionally jam. It could have been removed before sintering, but that ran the risk of snapping a whole tooth off. The other four bevel gears were meant to go around bearings, but they shrunk just anisotropically enough to not fit around the bearings.
Here is the “next step” of real parts that I started printing. Due to MakerBot’s slicer and the wall thickness of this part, a severe gap between walls occurred in this print. I finished my internship before these parts could be sent in for sintering, so I am not sure how the final version of them turned out.
Below is my report on this topic and the first appendix, which contains images of prints before and after sintering. If you are interested in the other appendices of this document, reach out to me and I’d be happy to help. I was unable to upload a .zip of the project for some reason (likely too large of a file size).