Selective Laser Melting in Powder Bed
LASERTEC SLM: Additive Manufacturing through powder bed fusion
Metallic 3D printing at high precision
Selective Laser Melting (SLM) is based on the so-called powder-bedding process. In a build chamber the size of which varies depending on the machine, metal powder is deposited layer-by-layer onto a plate and melted in a highly localised fashion, based on a CAD model. With each layer, the plate holding the part is lowered, allowing it to gradually grow in height. Once the construction process is complete, the unmelted powder is suctioned off then prepared for reuse. Increasing adoption of the technology has already led to a wider range of materials becoming available, including various steels and aluminium, cobalt chrome and nickel alloys, as well as copper and titanium.
The size of the build chamber permitting, multiple workpieces can be produced simultaneously. This method of 3D printing becomes even more productive when multiple lasers are used simultaneously. The precision of powder bed machines depends on various factors, including the laser’s focal diameter, the material used, the layer thickness, and the structure of the component. A focal diameter of 80 µm can, for example with steels, achieve a web width of 0.15 mm. With aluminium, it is 0.3 mm. Selective laser melting can also achieve extremely fine structures, such as internal cooling channels in tools. Where even higher accuracy is required, specific areas of the component can be post-processed using conventional methods.
The right powder-bed machine for every application
DMG MORI’s range of powder-bed machines includes the LASERTEC 12 SLM, which boasts a build volume of 125 x 125 x 200 mm. It has a focal diameter of just 35 µm, allowing for the creation of extremely fine structures. The LASERTEC 30 DUAL SLM has a build volume of 300 x 300 x 350 mm and is equipped with two lasers. As a result, productivity increases by up to 80 percent. With both models, rePLUG makes material switchover fast and uncomplicated. The powder module makes zero-contamination changeover possible in under two hours.