The past
The electron was discovered in 1897 by Joseph John Thomson at the Cavendish Laboratory in Cambridge. He proved that cathode rays consisted of particles that can be deflected by both magnetic and electric fields. He went on to determine the mass-to-charge ratio of those particles that were later named “electrons”. The cathode ray tube that J. J. Thomson used was essentially an electron beam source like the one used in Freemelt ONE. The electron was born in a beam!
Electron beam technology has been used to the benefit of society in many applications over more than 120 years since J. J. Thomson’s important discovery. Here are just some examples of 20th century electron beam applications: electron beam welding, electron beam machining, electron beam furnace, electron beam lithography, electron beam curing, electron microscopy, free electron laser and of course television CRTs being the main source of information and entertainment in most people’s homes in the second half of the 20th century.
Electron beam powder bed fusion, the technology in Freemelt ONE, was first tested in university research three decades ago. Selective melting of powder layers using an electron beam was performed in 1991 and published in a PhD dissertation from a university in Belgium. This technology is almost 30 years old!
Another important R&D achievement is a publication from 1996 from Japan that showed the feasibility of using laser heating of cathodes in an electron beam source. We have adopted and refined this technology which presents a robust and affordable alternative to other cathode heating principles.
Freemelt started in 2017 and since then we have developed new ways of using established knowledge in bringing to market a 3D-printer that is in all aspects suited for expanding the knowledge in advanced materials for future use, improving on existing applications and creating new ones!
The present
3D-printing of metals using powder bed fusion was first developed into a prototyping technology. Now it has also been qualified for production in numerous favorable cases where it provides added value compared with traditional manufacturing technologies. However, very few production cases (if any) exist where traditional manufacturing is easily implemented as an alternative. Still, the uptake of 3D-printing for production grows and more systems are sold now than ever.
Direct energy deposition and binder jetting are emerging alternative metal 3D printing technologies. Direct energy deposition can be used to print large parts but struggle with resolution and form stability. Binder jetting requires an additional heating step where the binding material burns away, and the remaining metal shrinks to final shape. Binder jetting is generally faster than powder bed fusion but is restricted with respect to material quality.
Laser powder bed fusion, in many respects similar to electron beam powder bed fusion, is today the dominating technology for 3D printing in metal, although binder jetting seem to grow faster at the moment. More companies than ever are producing laser powder bed fusion systems in a more differentiated price range than before. The interest for the unique opportunities with electron beam powder bed systems are also growing rapidly.
The future
3D printing of metals will never have a broad uptake in general manufacturing unless it can either provide cost savings or enable significant advantages compared with present manufacturing technologies. At Freemelt we believe that both these routes are available for electron beam powder bed fusion.
The route to such advantages is spelled MATERIALS. New materials have always been the route to success for new manufacturing technologies. This has not yet gained momentum in 3D printing of metals. Powder bed fusion has proven the potential to enable material advantages, but closed systems and powder supply requirements from machine manufacturers has slowed things down.
Cost savings comes from productivity. Powder bed fusion with laser-based systems is limited by available beam power and by lack of parallel printing. The most advanced laser-based systems have implemented multiple lasers to address both these limitations but with great complexity, limiting the advantages.
Electrons are much easier made than coherent photons and electron beam technologies for high beam power is a mature technology. At Freemelt we have developed an electron beam source with high quality beam properties all the way up to the maximum beam power of 6 kW. Combined with close to instantaneous beam positioning it is within scope to use all that power for melt processing at amazing build rates.
Freemelt’s technology therefore provide a path to a future where productivity matches the cost of manufacturing with the fastest present technologies, and at the same time providing excellent and new material properties. And this is just the start. We will continue to develop technology and opportunities with our customers and partners. With the benefits of an open 3D printing community, we aim to become a truly remarkable game changer towards sustainable and affordable manufacturing.
Come and join us now and let’s create the future together!
