Quality assurance of Additive Manufacturing in fabrication of large-scale lightweight structures

Purpose and goal:

The project focused on further development of a new concept for controlling additive manufacturing with laser and metal wire that enables using the method for crack-sensitive nickel alloys. Specifically in this project, control of the preheating current to the feedstock material was analyzed. The results show that high-speed control of the preheating current can significantly increase the process window (i.e. higher robustness) and the deposition speed. A doubling of both the process window and the deposition rate was demonstrated.

Expected results and effects:

The project focused on additive manufacturing of large-scale components where guaranteed material integrity is seen as an enabler for broad use of generative design for lightweight products. The project has demonstrated good conditions for the manufacture of lightweight structures in crack-sensitive materials using AM with laser and wire. Procada´s feedback control concept proved to be able to enable drastic increases in deposition rate and also make it possible to use previously unstable, but materially advantageous, process parameters.

Approach and implementation:

The project´s main activities consisted of the design and manufacture of a new high-power current regulator for filler wire preheating and deposition experiments with the updated control system. The performance of the control system was evaluated in Högskolan Västs equipment through a sensitivity analysis against process variations. The result was a considerable improvement in robustness when using originally unstable (but metallurgically sound) parameters compared to conventional control systems.