Affordable Aluminum 3D Printing with ValCUN’s Molten Metal Deposition

Whereas 3D printing has traditionally been used to make a lot of high-end parts in which weight saving and the texture or form make a high-value 3D-printed part worthwhile, lower costs would greatly increase the number of parts made industrially with 3D printing. Belgium based ValCUN is one of a new wave of firms that are trying to make metal 3D printing more affordable. Rather than producing thousands of parts for aircraft, spacecraft, and orthopedics, these firms are hoping to fabricate millions of parts for industry.

ValCUN was started specifically to meet the opportunity for more quotidian parts, avoiding lasers and powder to, as the company claims, be able to work with any feedstock. For now, the company is focused on aluminum. The company has even touted being able to use scrap metal and even cans. It also says that it is an “order of magnitude less capital intensive than existing powder technologies” and has “high build rates: comparable to welding or WAAM.” The small team is based in Ghent and has worked on making affordable metal printing for over four years.

Information on the startup, aside from the above video, is scarce. One of the first public pronouncements about their capabilities concerns the idea of manufacturing a heat exchanger element for insulated-gate bipolar transistors (IGBTs are similar to a MOSFET and can change conductivity).

In that case, the example was made up of

“three IGBTs [featuring] a generative design [that] increased cooling performance by 40%. Manufacturing 100.000 coolers with metal additive manufacturing technology known as SLM would not be possible within two years on one machine and would cost more than €100 per part. Combining diecasting with ValCUN’s AM technology makes it possible to produce this batch in 6 months at a unit price of a factor three to five times less.”

That’s a very interesting claim and, indeed, the company is offering to 3D print the most interesting cases, saying, “do you need a cost efficient cooling for serial production, contact Jan at jan.depauw@valcun.be. We select the five most interesting cases, calculate in a partnership how much added value we can create for you, resulting in a free demo part.”

It is good for us all that the firm is focused on lower end applications and millions of parts. It also wants to focus on much cheaper feedstock and lower cost machines, which should make 3D printing metal parts affordable. How does it work? On this details are rather scarce. The firm has referred to its technology as “molten metal deposition” and has mentioned that it uses aluminum wire feedstock. From one of the few images, we can see that it is a spooled metal wire that is melted.

The technology works through extruding preheated molten metal onto a workpiece that is heated through electric current, which creates a plasma jet. This plasma jet warms the surface onto which the melted material will be deposited, exactly where it will be deposited. Through precise preheating and use of plasma, the new layer is then fused with the existing layer. 

With a “preheated localized plasma welding” approach, one could see how one might get a high deposition speed and have a relatively low cost machine. In ValCUN’s process, the metal is first melted, then the workpiece is heated using plasma and the material is deposited, meaning less overall heat and energy are expended for the process than if you’d have to heat an entire chamber for example. I interviewed Jonas Galle, the inventor of the technology and founder of ValCUN to find out more.

Galle said that “molten metal deposition, MMD…was invented to counter the disadvantages of powder bed fusion processes…which are slow and expensive.” With MMD “we can even use granulate” and “with a cheaper feedstock and a lower cost machine, because we don’t use lasers, we can make direct metal 3D printing more accessible.”

He mentions that in their “reverse welding process“, “there are trade-offs of course and now, for example, our resolution is 0.4mm.” There are a lot of applications for which this resolution is sufficient enough. After all, post-processing of sealing surfaces and fittings is needed anyway, even for the high-resolution powder bed technologies. The company focuses on applications that fit those constraints, however, and is able to, due to their technology, work with “aluminum and later on copper.”

MMD means that less energy has to be expended on heating and, “especially with aluminum and copper, there would be lots of temperature loss” with other technologies. MMD’s additional advantages are that “there is less stress on parts, and fewer problems with expansion and cracking.” In their development, the team has spent a lot of time on temperature control and temperature management. This “better heat control” is important in making the process cost-efficient and more reliable. Through “depositing molten metals….and plasma heating,” they feel that they’ve created a comparatively low-cost technology that can be deployed with lower up front costs and lower cost per part. 

For right now, the firm is looking for applications. Indeed they’re urging people to contact them should they have interesting applications for the aluminum materials. Given their resolution and cost, they’ve already determined that heatsinks and heat exchangers are a good application, as would be manifolds. They’re interested however in finding out what else may be out there.

Their technology is also suitable for hybrid manufacturing. This means that the technology can be used in combination with other manufacturing technologies by “3D printing on top of prefabs obtained by milling, extrusion, and injection molding.” In this way, “the advantages of the ‘relative low speed’ additive manufacturing can be combined with the ‘fast and state-of-the-art’ technologies, especially for serial production. Many of the metal additive manufacturing technologies are limited in handling these kind of applications.”

ValCUN really wants to make possible “serial production of mainstream parts.” At the moment, they’re looking to make “shoebox-sized parts…in a test phase,” but their build volume is “800 by 500 by 400mm,” which would have them blow past a lot of the competition in metal 3D printing. ValCUN itself is a privately held startup and they are in the midst of a capital round at the moment. They are currently doing pilot projects and will launch their first commercial release in 2021.