In the field of metal 3D printing, processes based on powder forming, such as SLM, SLS, EBM, etc., are mostly known, but the research on metal paste printing in the industry is relatively small. It is also mainly based on laboratory research in universities, and the application cases of such printing processes in the market are not common.
Mantle, a foreign startup 3D printing company, chooses metal paste printing as their research direction, which is very similar to FDM technology, only the material changes from wire/particle material to metal paste. The company's co-founder and chief scientific officer, Dr. Steve Connor, explained in detail the technical reasons why his company uses slurry as a material in its metal 3D printer, rather than filaments, powders or liquids like almost all other metal 3D printer manufacturers use.
Technical principle
Mantle's TrueShape technology prints, shapes and sinters precision metal parts from CAD files at a fraction of the time and cost of traditional manufacturing.
The technical process is divided into three steps: printing, cutting and sintering. First, the Flowable metal Paste material is printed into the shape of the part using a precision positioning system and an extrudation-based printhead. At the same time, a tool is used to cut the deposited layer at high speed, improving the surface finish and detail of the part. Finally, in a high-temperature furnace, the part is heated to a temperature slightly below its melting point, melting into a dense solid metal part.
Mantle, as a new startup in the field of 3D printing, has slowly come into the public eye recently, which is related to the fact that their company has not done a lot of related product exhibitions. Mantle's market positioning is industrial metal tools, and their entire system, as well as the metal 3D printing process launched, is also designed around this market.
In short, the process characteristic of Mantle is to use a slurry extruder to precisely deposit metal slurry, so as to achieve the effect of billet. The deposited green billet is then heated to remove the binder and the metal particles sintered together before a CNC milling action is performed to smooth the surface. This is repeated layer by layer until the object is built.
Mantle, unlike most 3D printer makers, did not follow the model of starting with the technology and then finding the market. Instead, they chose the market first and only then targeted the technology problem.
Metal 3D printing is now a widely used technology, with several vendors offering related products. Most manufacturers choose to use the powder bed melting (PBF) process, where the powder is selectively melted layer by layer by moving a high-energy heat source. Other metal forming processes include printing from liquid metal nanoparticles (such as XJet) and high-purity metal wires (such as coaxial wire feeding laser welding).