Brief introduction to the operating principle of SLS technology

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The operating principle of SLS technology is as follows: the solid powder is selectively sintered in separated layer by the laser; meanwhile, the sintering molding solidified layer will be overlaid layer upon layer and form the parts with required shape. The whole technology process includes the establishment of CAD model, data processing, powder spreading, sintering, postprocessing and so on.

metal powder spreading

The whole process unit is composed by powder cylinder and moulding container. When it works, the piston of powder cylinder (piston that sends powder) will rise and the powder will evenly cover a layer on the moulding container piston (working piston) by powder spreading roller, afterwards, computer will selectively sinter the solid powder material so as to form a bedding surface of the part by controlling the two-dimensional scanning track of laser beam according to the slice mold of the prototype. After spreading a layer of powder, the working piston will descend by a layer and the powder spreading system will spread new powder. Scan the new sintering layer with laser beam. Doing this work in circulation and overlay the powder layer upon layer until three-dimensional part is formed. At last, recycle the powders that have not been sintered and put them in the powder cylinder and fetch the molding part. Regarding the metal powder laser sintering, by heating the workbench to a certain temperature before sintering, it can not only reduce the thermal deformation in the molding process, but also will be beneficial for the combination between layer and layer.

Compared with other rapid prototyping (RP) methods, the most prominent advantage of SLS is that it has many kinds of moulding materials. In theory, any powder material that can form the interatomic bonding after being heated can be used as the mouldind material of SLS. At present, materials that can be successfully used in moulding and processing of SLS technology include paraffin, macromolecule, metal, ceramic powder as well as the composite powder materials of them. As SLS moulding materials have large variety as well as can save material and the moulding part performance is widely distributed and can be used in many fields, besides, no complex support system is needed in the SLS technology, the application of SLS is becoming wider and wider.