|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Alloy Development and Powder Manufacture for Additive Manufacturing
||Preventing the Coarsening of Al3Sc Precipitates by the Formation of a Zr-rich Shell during Laser Metal Deposition
||Philipp Kürnsteiner, Markus Benjamin Wilms, Andreas Weisheit, Eric Aimé Jägle, Dierk Raabe
|On-Site Speaker (Planned)
As neighboring tracks and subsequent layers are deposited during Additive Manufacturing processes such as Laser Metal Deposition (LMD), the material experiences a cyclic reheating. The idea behind the present study is to exploit this intrinsic heat treatment (IHT) of LMD to produce parts that are already precipitation hardened after manufacturing, avoiding the need for a post heat treatment. Two hypereutectically Sc-alloyed Al alloys were studied: the commercial Al4.5Mg0.66Sc04Zr Scalmalloy® and an Al1.0Sc0.6Zr alloy. It will be shown that high number densities of Al3(Sc,Zr) precipitates in the range of 1021-3x1023m-3 can be achieved by exploiting the IHT. Different IHT conditions were analyzed by lifting out Atom Probe Tomography tips from different layers of multi-layer samples. In the Scalmalloy®, the precipitates coarsened with increasing strength of the IHT. In the Al1.0Sc0.6Zr alloy, the precipitates formed a Zr-rich shell that prevented coarsening. This enabled uniform in-situ precipitation strengthening throughout the build-height of multi-layer samples.
||Planned: Supplemental Proceedings volume