Related Vendors

Fraunhofer-Institut für Lasertechnik

AMPCO METAL Deutschland GbmH

Renishaw plc

Ramada Acos

Unique large-volume 3D printer developed by researchers

At Fraunhofer ILT, a 5-laser PBF-LB/M machine in gantry construction was developed, which currently has a build volume of 1,000 × 800 × 350 millimetres. Unlike conventional systems, it works with a movable processing head and local shielding gas flow, so that the build volume can be scaled linearly along the machine axes under the same process boundary conditions (shielding gas flow velocity, laser beam deflection angle, etc.), explain the Aachen-based researchers. This would make it possible to additively manufacture even larger tools than the tool inlay considered in this project, which has a volume of over 20,000 cubic centimetres and a bounding box of 515 × 485 × 206 millimetres. However, in order to minimise the critical temperature gradients associated with large-volume tools, a heatable substrate module was also developed, as we learn further on. The build platform now reaches a temperature of 200°C, which means that each new layer cools down not to room temperature, but only to a predefined thermal plateau. This idea reduces thermally induced stresses and the risk of cracking during the printing process. The combination of large build space, high process stability and active preheating makes this system one of the first LPBF systems worldwide that is suitable for the economical production of near-net-shape die-cast moulds, even for mega or giga casting.

Printed transmission already in use at Toyota

More specifically, the project involved manufacturing an additively produced tool insert for a gearbox housing that is already in use at Toyota today. The die-cast mould insert also includes a complex network of contour-close cooling channels, which demonstrates the clear advantage of additive manufacturing for this purpose. This is because such a design would not be possible using conventional machining. For the additive tool design, the project team relied on a hybrid process for the specially manufactured preform, which already had vertical cooling channels. However, the precise positioning and reliable connection of both components still placed high demands on machine calibration, precision and process control. Such hybrid structures are said to have the potential to reduce construction time and costs, because the relatively expensive PBF-LB/M process is only used in those component areas that cannot be produced conventionally. The researchers then designed the complex cooling structure in such a way that critical areas of the mould are effectively temperature-controlled during die casting. As mentioned above, this reduces the thermal load. At the same time, additive manufacturing offers the possibility of drastically shortening throughput times. Instead of the complex machining of several tool components and their assembly, a consolidated, continuous additive manufacturing process is sufficient. Incidentally, the die-casting mould for Toyota was manufactured in less than ten days, including all preparatory steps, as is emphasised. For OEMs, this means proven shorter development cycles and faster market introduction of new vehicle platforms.

Gallery

(ID:50545749)