DMLS

Direct Metal Laser Sintering (DMLS)

Direct Metal Laser Sintering is one of the few 3D printing technologies that directly creates a metal part from its 3D CAD model. This process is an advancement of the powder metallurgical process, a mature metal-molding technology that uses heat and pressure to form powdered metal parts. The working material for this 3D printing process is finely powdered metal. Typically, the size of the metal particles is 20 – 40 microns. The particle size and shape limits the resolution of the final part. Other limiting factors for the resolution are layer height and laser spot diameter. Printable layer heights are approximately the maximum size of the metal powder particles used.

The DMLS fabrication process works as follows:

I. The DMLS printer hopper is filled with the desired metal powder. The powder is heated to a temperature near the sintering range of the alloy. The printer uses an inert gas which protects the heated powder and part as it is being built.

II. The build begins with dispensing a thin layer of metal powder onto the build platform. The laser then begins its path for this layer, selectively sintering the powder into a solid. The sequence of dispensing a layer and sintering continues until part completion.

After the part is left to cool, the surrounding loose metal powder is removed from the printer. The last steps include support removal as well as any post-processing needed.

DMLS parts can be treated like metal parts produced by conventional metal working for further post-processing. These may include machining, heat treatment and/or surface finishing.