How do metal 3D printers work?
Are you planning on producing metal parts? If this is the case, there are a couple of machining processes you could potentially employ. Requesting a CNC machining quote is a great example of this, but it is also possible to 3D print metal products. You could do this with the help of a 3D printing service, although you could buy your own metal 3D printer as well of course. Which option you are going for will depend on your situation, but it is definitely important to know how the metal 3D printers work. Thankfully this will be explained below.
SLM (Selective Laser Melting) process
SLM is the abbreviation of Selective Laser Melting, which is a process that creates products additively as it fuses metal powder particles together. With this process, the metal part will be created layer by layer. Eventually your 3D design will be created because of this, which is also the case for other additive manufacturing techniques. A 3D printer that uses Selective Laser Melting to produce parts consists of a build chamber that is filled with an inert gas. Usually this is either nitrogen or argon at oxygen levels below 500 parts per million. This is needed to create the optimal conditions for the melting processes. Furthermore, SLM fully melts the powder. Because of that, it needs to reach a very high temperature. The advantage of this key element is that it allows the metal to form a homogeneous part with amazing resistance.
DMLS (Direct Metal Laser Sintering) technology
DMLS, or Direct Metal Laser Sintering, can be used as well. 3D printers used in DMLS technology additively manufactured parts by sintering fine particles of metal powder to fuse them locally. Because of this, it is very similar to the SLS process, which can be used to produce plastic parts with the help of a 3D printer. However, there is a main difference; the sintering temperature. In fact, polyamide must be sintered at a temperature between 160°C and 200°C, while metal melts at a temperature between 1510°C and 1600°C, which means that higher power lasers are required to reach this temperature. Furthermore, in DMLS a roller will lay down a layer of the metal powder. The laser will then sinter this powder, while the build platform will lower a bit before the roller applies a new layer of the powder. The process is constantly repeated until the 3D part is produced.
Additive manufacturing process: Binder jetting
Binder Jetting is another additive manufacturing process that can create metal parts as well. This method works with a binding agent, as its name already suggests. This liquid binder is deposited on the powder, depending on the 3D file you want to make. Furthermore, the powder used during Binder Jetting is slightly cured, so it solidifies between each layer. When the 3D printing process has been completed, the build box will be removed from the printer. It is then placed into an oven to cure. When this is over, the parts can be extracted from the build box. The remaining powder should be removed with the help of air blowers and brushes.
Story by Tim Hoogewerf