Selective Laser Melting

Layer by layer on the way to the functional workpiece

Selective Laser Melting (SLM™) is a generative production method in which the desired components are produced directly from 3D data. Based on the data at hand (standard format STL), even highly complex parts can be produced from different metallic materials.

With the SLM™ method, the workpiece is constructed in a three-dimensional layer structure. To accomplish this, the metal is applied in thin layers of very fine powder and, using a laser beam, melted onto those areas where the workpiece will be developed. Depending on the surface quality and production speed requirements, the powder is automatically applied with layer thicknesses of 20 to 100 µm. In the following step, a powerful fibre laser selectively melts the designated areas. Sharp focusing provides the laser beam with a very high power density by which the material is melted in a very precise manner. Thus, workpieces with an absolute density can be produced with wall thicknesses from 40 µm on up.

So funktioniert SLM

When the melting process is finished for the particular layer, the platform is lowered by the respective thickness, and another layer of powder can be applied. The workpiece is fabricated layer by layer in this manner. The duration of the process, which takes place in closed inert gas atmosphere, is dependent on the amount of material used and the number of layers – rather than the complexity of the component.

The layer structure facilitates the production of highly complex lattice or honeycomb structures, which cannot be produced using other methods. With the SLM™ process, the material is therefore only built up where required by the intended use and future strain requirements. One of the benefits here is for example the minimization of weight due to the optimized material usage.

Components of absolute impermeability and mechanically heavy duty quality are produced by means of SLM™, the material properties of which nearly equal those of conventionally produced components. Depending on the intended use and just like the conventionally produced components, they can be reworked using any other method.

This is what makes SLM™ technology a sensible alternative…

  • When a functional metal component has to be produced from three-dimensional construction data in the shortest possible time. SLM™ makes prototypes available using the CAD draft and without any lengthy detour via toolmaking. This process is not only faster, but also the most economic way to generate a perfectly functional sample.
  • When, for example, complex components with very complicated hollow or lattice structures cannot be manufactured or only manufactured by utilizing very complex methods using conventional processes. SLM™ technology, unlike other methods, still only affects the cost marginally when considering the complexity of the component to be produced.
  • When only a limited number or unique pieces are to be produced.