The Fraunhofer Institute for Laser Technology ILT has partnered with powder manufacturer MacLean-Fogg and Toyota to develop a 3D printing solution for manufacturing large die casting molds used in automotive production. The collaboration addresses the automotive industry’s shift toward fewer, more complex structural components that require larger and more durable casting tools with shorter development times.
The project centers on a gantry-based powder bed fusion laser beam melting (PBF-LB/M) machine with a scalable build volume of 1,000 x 800 x 350 mm³. The system features a movable processing head, local shielding gas guidance, and a heatable substrate module that reaches 200°C to minimize temperature gradients during production. This design allows the build volume to be scaled linearly while maintaining consistent process conditions.
Previous attempts to 3D print large die casting molds faced two main obstacles: insufficient build volumes in conventional machines and material limitations with traditional tool steels. Large components exceeding 20,000 cm³ in volume typically experienced cracking, thermal distortion, and poor mechanical properties during both the printing process and subsequent heat treatment.
“To overcome these limitation, we need a new generation of machines and materials specifically tailored to the requirements of large-format HPDC tools,” explains Niklas Prätzsch, Group Leader LPBF Process Technology at Fraunhofer ILT. “It was precisely this combination that was the subject of the latest changes we have implemented.”
The project utilizes MacLean-Fogg’s L-40 steel, which was developed specifically for additive manufacturing applications. The material demonstrates reduced cracking tendency compared to conventional tool steels and achieves 48 HRC hardness, 1420 MPa tensile strength, and over 60 J notched impact strength in the as-built condition. “The key to success lies in the L-40 material from MacLean-Fogg, which is tailored to the requirements of PBF-LB/M,” comments Prätzsch.
The system successfully produced a tool inlay with a volume exceeding 20,000 cm³ and dimensions of 515 x 485 x 206 mm³. The technology enables the creation of complex internal cooling structures that cannot be manufactured through conventional processes, potentially extending tool service life compared to traditional molds.
Source: ilt.fraunhofer.de