SLM fabricated die insert for press hardneing

UPB & Benteler AG, Apex Generative Design

Selective laser melting (SLM) is a powder bed-based additive manufacturing process for the production of metallic, highly complex components. With regard to tool manufacturing for forming production (e.g. extrusion, deep drawing), an almost unrestricted freedom of design enables the integration of cooling channels close to the contour in order to reduce hot spots, so that the component distortion of the semi-finished product is minimized, the service life of the tool is extended and the process time is shortened. As a result of the near-contour filigree production, machining can also often avoided.

Achievements

The process parameter study required for this includes the targeted variation of the volume energy density using a design-of-experiment approach. The achievable relative density is analyzed using cube samples with dimensions of 10 × 10 × 10 mm3. In addition to the relative density of > 99.99 %, the process speed and the surface roughness are defined as target parameters. Increased coating thickness has a significant effect on process time, so that coating thicknesses of 100 μm and 150 μm are targeted instead of the standard 25 μm to 50 μm. Following the determination of the process parameters, the surface roughness is addressed in order to set a low roughness for the uppermost two layers through a targeted parameter adjustment.

In parallel to the development of the process parameters, the topology of a tool insert for hot forming with integrated near-contour cooling is optimized. An existing conventional mold, for which the load cases and the thermal input are known, is used as a demonstrator.

With the generated results of both project focuses, an economic efficiency analysis is finally carried out with regard to the conservation of resources.

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Prof. Dr.-Ing. habil. Mirko Schaper

Direct Manufacturing Research Center (DMRC) (until 2022)