Metallic additively manufactured components: Challenges and solutions in the post-processing process

Metallic additively manufactured (AM) components are essentially "welded" to the build plate, which means that the components cannot be easily removed. Even after removal, they require post-processing before they are ready for use. The following sections highlight some cost factors and important post-processing procedures for AM components, in particular the essential heat treatment process.

The layer-by-layer forming of the parts creates internal stresses through the heating and cooling of the metal. These stresses must be eliminated before the component can be removed from the build plate; otherwise, the parts may warp or even break. To reduce the pressure on the components, a sufficiently large furnace or corresponding system (preferably with environmental control) is required that is large enough to accommodate the entire plate. Many experts recommend the use of a furnace in an inert environment to minimize oxidation on the surface of the parts. Others prefer vacuum furnaces, which, however, are significantly more expensive (100,000 US dollars versus 10,000 to 30,000 US dollars).

Through collaboration with customers and several universities, it was determined that vacuum processes offer advantages:

These advantages are particularly important in aerospace and medical applications, where strict regulations must be met to reduce surface contamination and maximize mechanical properties.

In summary, vacuum heat treatment is an essential step in post-processing, particularly for specific components and materials processed with SLM technology.