Desktop Metal might have set the ball rolling back in 2017, but it seems HP is getting very serious about 3D metal printing at industrial volumes and automotive-grade production quality. The technology is called HP Metal Jet, it’s 50 times faster and significantly cheaper than existing methods, and pilot programs are already underway.
Similar to the Desktop Metal production system, HP’s Metal Jet printers use layers of fine metal powder, sprayed in precise patterns with binding agents by a print head that passes over from side to side. A second vertical head spreads the next layer of powder in between passes, so the binder head can operate in both directions.
The print bed is cured, to evaporate any liquids and turn the binder solution into something that acts like a hot-melt adhesive. Next up is a de-caking process to remove excess metal powder, which can be re-used in a low-waste process, after which the final part is sintered – brought up to just below its melting point – in a furnace, a process which decomposes the binding agent and fuses the metal particles together into a single, extremely dense and solid part.
From there, the part can be polished, machined or otherwise finished for final use. Like all 3D printing processes, this one allows the creation of extremely complex parts, at short notice and without requiring any re-tooling. Initially, HP Metal Jet will only print in stainless steel, with other metals under investigation for suitability.
In terms of resolution, a Metal Jet voxel (the 3D equivalent of a pixel) will be around 21 microns in length and width, representing a 1200dpi 2D printing process, and somewhere between 50-100 microns in height, because that’s the layer thickness accuracy HP can achieve. For reference, a human hair is generally about 50 microns wide, so we’re still talking a high degree of accuracy here.
Each Metal Jet production machine will cost less than US$400,000, and will give you a maximum build volume of 430 x 320 x 200 mm (16.9 x 12.6 x 7.9 inches).
HP is timetabling the Metal Jet roadmap in stages. Right now, it’s already operational in two pilot programs. Metal injection molding specialist Parmatech is using it to produce medical equipment like surgical scissors and endoscopic surgical jaws, and GKN Powder Metallurgy is producing parts for automotive and industrial giants like Volkswagen and Wilo.
In 2019, HP will start up a production service, which will allow manufacturers to upload 3D design files and have them printed out in industrial quantities by Parmatech and GKN. The printers themselves will begin shipping in 2020, with “broad availability in 2021.” Desktop Metal, for its part, has pushed back availability of its production machines from this year to 2019.
So, this is happening folks. Buckle up and let’s hope we start to see some really interesting designs – potentially some of those weird generative design ideas – making their way into mass-market production items in the next few years.