3D Metal Printing

A printable suspension of metal powder and a binder is pressed in a screen printing process through a computer generated mask, followed by a hardening step. In the next step a layer-on-layer printing is repeated until a 3-dimensional part is manufactured. A first heat treatment is applied to remove the organic binder; subsequently the remaining metal powder is sintered to structures with high precision and good mechanical stability. The residual minimal wall thickness and channel width amounts about 100 µm. In contrast, the maximal structure height may add up to a couple of centimeters. Hence, exceedingly high aspect ratios are feasible. The method enables the production of 3-dimensional structures with horizontal apertures or closed channels.

 

 

Materials

Because of the powder route it is possible to use any metal or alloy which is available as a powder. The focus at Fraunhofer IFAM lies on relevant materials for industrial purposes, especially on Fe, Ni, Ti based metals.

Applications

The direct typing technique is promising for the manufacture of complex cellular P/M structures like micro fluidic devices, catalyst carriers, or mechanically optimized structural parts. For example the production of monolithic micro heat exchangers or other micro fluid devices seems to be possible. Thus a substantial progress to current stack design may be reached.

The benefit of the direct typing process is a good upscaling possibility for industrial purposes at reasonable costs in a fully automated process.