Thermal Post Treatment for AM Part Applications
Prof Christoph Broeckmann (RWTH Aachen University, Germany)
Mrs Adeline Riou (ERAMET Group, France)
HIP of AM Components – Some Key Aspects
Dr Iñigo Iturriza (CEIT, Spain)
Powder based AM technologies are experimenting a strong growing in the last years and have a large potential for the net shape processing of complex parts as well as the introduction of optimized design. As for castings, Ni based superalloys, Ti and Al alloys are under development mainly for aeronautic and medical sectors. However, some defects inherent to the processing have been found. Cracking, porosity, residual stresses, columnar grain structures, segregations are common issues that have to be faced up. HIP emerges also in AM as a post-treatment able to improve the microstructure of as-built parts healing some of the previously mentioned defects and consequently increases their mechanical properties and decreases their dispersion. Therefore, HIP plays a key role widening AM applications making AM more consistent. However, correct application of HIP requires not only an optimization of the process parameters but also a suitable fit with the rest of the processing steps. The type of defects that can be eliminated, the optimization of process parameters for some of the most common AM materials and the risk of post heat-treatment are going to be shown in this presentation.
How Al-Powder Quality is Affecting the Related (HIP) Material Properties After 3D Laser Powderbed Printing - Lessons Learnt from an Aerospace Manufacturing Perspective
Mr Frank Palm (Airbus Defence and Space GmbH, Germany)
High quality Al powders are a pre-requisite for successful laser-powderbed fusion (LPB-F). Currently many investigators are focussing on morphological aspects of Al-powders quality like powder size & spherical appearance. Anyhow, reliable & unrestricted processability of Al-powders is an undiscussable must in order to industrialize 3D-powderbed printing comprehend-sively. Otherwise it will become an incalculable technical & commercial risk.
A “hidden” however even more critical aspect of Al-based LPB-F is the inevitable “oxide challenge” because Al-powder need to be passivated (defined oxidized) to assure safe handling. These oxides are affecting melting & consolidation propensities during material generation as well during subsequent post build-up heat treatments. Hot isostatic pressing (HIP) can “repair” inconsistent (defect prone) LPB-F Al-micro structures. There seems to be a correlation of oxide amount trapped in the LPB-F process and the efficiency of HIP.
BEAMIT Philosophy, The Correct Way to make A.M. Process Reliable, Stable and Repeatable
Mr Maurizio Romeo (Beamit SpA, Italy)
A.M. process is not so much "simple 3D printing process" as an entire, complex, critical new metallurgical process. And as such should be considered and faced up. Starting from the first critical step, the powder and its metallurgy, including analysis and controls, to any, complete reports and checks (DT and NDT). Passing through the entire melting process control (both laser both EBM) and proper (completely new) heat treatment for this kind of new A.M. metallurgy.