Powder bed fusion with electron beams is very similar to the process with laser beams. The main difference is obviously the heat source, which is an electron beam and not a laser. This also means, that the process has to be done in a vacuum. Since there are even more parameters to account for in the PBF-EB/M process, it is used with a smaller range of materials. Additionally brittle materials can be processed. The problem with the PBF-LB/M process for brittle materials are the fast cooling rates, which lead to solidification cracks. PBF-EB/M does not have this problem, since the powder bed is heated to high temperatures (>870 K) and the cooling rate is significantly reduced, which also leads to a coarser grain structure compared to PBF-LB/M. Through the high temperature the powder bed reaches, it needs to cool for a long time, before the parts can be removed.
PBF-EB/M
