Electron beam melting (EBM) is an additive manufacturing technology that uses an electron beam instead of a laser as its heat source to melt metal materials. (It does not work with thermoplastic polymer materials.) Basically, electrical charge produces the reaction between the power and the beam, which causes the powder to solidify.
Two vendors are involved with EBM.

Arcam, now owned by GE Additive, offers a proprietary powder bed fusion version. In this version, a 3 kW electron beam generates the energy needed for melting and for producing a high number of parts (depending on part size and shape). Metal powder is melted in a high vacuum, layer by layer until the part is created. A vacuum environment ensures a clean and controlled build, important to maintaining the chemical specification of the build material. The parts made with this process are free from residual stress with material properties better than cast and comparable to wrought material. Because fully dense parts can be made here, this method is used in the medical, aerospace and automotive markets.

The Arcam machines use state-of-the art electronics that change the beam position, focus settings and astigmatism to enable fast and accurate beam control.

Sciaky is another vendor that offers EBM technology. In the Sciaky system, an electron beam (EB) gun deposits metal (via wire feedstock), layer by layer, until the part reaches near-net shape and is ready for finish machining.

Sciaky’s system uses the IRISS (Interlayer Real-time Imaging & Sensing System), a patented Closed-Loop Control that ensures consistent part geometry, mechanical properties, microstructure, metal chemistry and more part features. Gross deposition rates range from 7 to 25 lb (3.18 to 11.34 kg) of metal per hour, depending upon the selected material and part features.