Metal 3D printing is currently dominated by powder-based techniques like SLM (Selective Laser Melting). These processes yield incredibly precise parts, but the build times are slow. Furthermore, dealing with the powder increases manufacturing complexity: Whenever the powder is transported, loaded into the machine, or cleaned up afterwards, rigorous steps must be followed to prevent the loose spread of powder. (The powders are flammable and present an explosion risk, and can also cause respiratory issues for workers.) Following all of these steps adds cost, time, and risk.

A Spain-based company called Meltio has developed a new metal 3D printing technology that does away with powder-based hassles. Rather than powder, Meltio's feedstock is metal wire, which is easy to handle on spools. The wire is fed into a point where three to six low-power diode lasers converge, creating what's known as a "melt pool." (This is sort of like the "contact patch" on a car tire, in that it's paradoxically always moving, yet always in the same place, if that makes sense.) This turns the wire into molten metal that is delivered in layers, as with FDM 3D printing.

There is no waste. The technique only consumes the amount of wire needed to fabricate the part. There is no powder clean-up afterwards, and storing spools of wire is straightforward .

The technique is called LMD, or Wire-Laser Metal Deposition. It can handle stainless steel, titanium, aluminum, copper and a variety of alloys. It can also feed in two different wires for the same part, meaning you can mix metals. A part could be printed with tool steel on the outside, while its core is printed with cheaper mild steel. Or a part could be printed with a combination of corrosive and anti-corrosive metals, for instance if one face will be exposed to the elements.

It can also print onto or around existing parts, as seen below. This opens up some fascinating repair possibilities.

Afterwards, parts can be conventionally machined if greater precision is required. (Meltio reckons this is less wasteful than if you'd machined the entire part out of a bilet, as much less material is removed.)

The company points out that you needn't buy an entire machine from them; their technology can be retroactively added onto existing robot arms or CNC machines.

Here's a demonstration of what the Meltio system can do:

Enter a caption (optional)