In the same way that a cavity can be generated directly by stereolithography, it also is possible to build tool cavities directly using the laser sintering process.
With DTM’s RapidSteel (also referred to as RapidTool), digital models of the core and cavity geometries are created and sent to a Sinterstation machine for fabrication in RapidSteel powder. This material consists of particles of mild stainless steel that are coated with a thin layer of a polymer binder material. The Sinterstation produces green parts that are then fired in a furnace. The furnace removes the polymer binder and infiltrates bronze into the mold inserts through capillary action. This process produces a fully dense tool that consists of about 60 percent steel and 40 percent bronze. The inserts are then finished, drilled for ejector pins, and fit to a mold base.
The process produces a durable mold that can be used for injection-mold tooling, as well as die-casting applications. RapidSteel molds have been used to cast hundreds of aluminum, zinc and magnesium parts. The process allows for complex geometries and RapidSteel molds can withstand the conditions of injection molding. However, RapidSteel requires finish machining and polishing that can be time consuming.
The advantages are speed, good tool strength and its use for injection molding and die-casting. Disadvantages are equipment cost and size limitations.
SLS selection laser sintering technology is to pre-sludge a layer of powder material (metal powder or non-metal powder) on the workbench, and then let the laser sinter the solid part powder according to the interface contour information under computer control, and then continuously circulate, layer by layer. Stacking molding. The method has the advantages of simple manufacturing process, wide material selection range, low cost and fast forming speed, and is mainly used for directly producing rapid molds in the foundry industry.