Powder bed additive manufacturing uses fine powders (5-50µm) to build parts layer by layer. The machine comprises a powder supply, a build platform, a powder spreader, a laser, and a pointing and focusing system. The powder spreader spreads a thin layer of powder on the build platform. The laser melts the powder in locations where the part is to be. When the layer is complete, the build platform is moved downward by the thickness of one layer and a new layer is spread on the previous layer. The melting and spreading process is repeated as the part is build layer by layer. When complete, the un-melted powder can be recovered and used again. The part can then be heat treated if necessary and removed from the build platform. The process is illustrated in the animation below.
The process is shown schematically in the following graphic.