😲 Did you know that you can print 100% metal parts on your home 3D filament printer?
A hint: it’s not like making a mold to cast molten metal – much easier!
We show you how to print metal with your FDM printer and introduce you to all the 3D metal printing technologies that exist.
Filament for printing metal parts
You may have noticed that some manufacturers sell filament with metal dust. These are materials that imitate the metal finish on your printed pieces.
But we are not talking about this, we are talking about filament that is printed in 3D and used to make 100% metallic printed parts.
What material is it? It is the BASF Ultrafuse filament from the German company BASF. It is a filament with a large amount of metallic dust that is printed with a conventional FDM 3D printer. After printing, the pieces have to follow a chemical washing and sintering process in an oven so that the metal powder is fused into a single solid metal piece.
Here is a video where you can see what results can be achieved with this type of 3D metal printing.
What is the filament made of? The content of the BASF Ultrafuse 316L filament is, as its name suggests, 316L stainless steel, a very popular steel used in applications where corrosion resistance is a critical feature, as it is more expensive and stronger than the most common stainless steel (304).
The filament coil contains 90% metal by mass; the rest of the material is the thermoplastic which makes it remain in thread form and flow through the printer extruder.
Examples of parts made with this filament
As you can see, the parts that go through the whole post-processing process have the characteristic lines of 3D layered printing and some filament sticking. The pieces can be sanded both in green (this is what the piece is called before it is washed and sintered) and in its final metallic form. They can also be polished, shot-blasted, etc.
The post-processing of the metal filament
As we said, with this filament we need a post-processing to obtain the final metal part.
The post-processing is usually done in an external company. Usually when you buy the coil it includes in its price the post-processing of the parts you manufacture with it. The technologies for post-processing of powder metal and plastic parts already exist for MIM (Metal Injection Molding) manufacturing, so it is possible to find suppliers who focus on these phases.
The process that the part goes through until it is a steel mass is as follows:
- Printing (green part). Printed on a conventional FFF printer with an abrasive resistant tip
- Washing/Debinding (brown part). The printed part is immersed in an atmosphere of vaporized nitric acid (HNO3) and heated to remove the plastic from the part so that only the metal dust remains. The result is the phase known as the brown part.
- Sintering. The brown part is placed in an oven where it is subjected to high temperatures without melting it so that the powder particles are completely fused and almost 100% desiccated. During this process the part shrinks, so it is necessary to print it with a margin that is established in the design process.
👉 How to print metal on your own printer
Now the most important question: can I use any printer to print it? Yes, you can print with conventional FDM desktop printers: Ultimaker, BCN Sigma… in 1.75 and 3mm filament. The only thing you need is a steel nozzle to resist the abrasion of the metal filament.
These are the printing parameters of the BASF Ultrafuse 316L filament, judge for yourself:
And how much does it cost? It’s starting to be distributed and can be found at Matterhackers for $465 a reel.
¿Do you want to try 3D metal printing?
We have not yet been able to get hold of a BASF Ultrafuse coil to test it, but we are very interested in starting to print metal parts. If you want to ask us for a quote for this or any other project, just leave us a message and we will help you make it happen:
So how do you immerse your parts in vaporized nitric acid and heat them at home?
That’s not for doing it at home. It’s done at an specific vendor. This kind of filament spools often come with the postprocessing service included, you have to ask when you buy the material.