Massive nanoprecipitation in an Fe-19Ni-xAl maraging steel triggered by the intrinsic heat treatment during laser metal deposition
By P. Kürnsteiner, M. B. Wilms, A. Weisheit, P. Barriobero-Vila, E. Jägle, Dierk Raabe. 2017
287 citations recorded by the source corpus.
Abstract Due to the layer-by-layer build-up of additively manufactured parts, the deposited material experiences a cyclic re-heating in the form of a sequence of temperature pulses. In the current work, this “intrinsic heat treatment (IHT)” was exploited to induce the precipitation of NiAl nanoparticles in an Fe-19Ni-xAl (at%) model maraging steel, a system known for rapid clustering. We used Laser Metal Deposition (LMD) to synthesize compositionally graded specimens. This allowed for the efficient screening of effects associated with varying Al contents ranging from 0 to 25 at% and for identifying promising concentrations for further studies. Based on the existence of the desired martensitic matrix, an upper bound for the Al concentration of 15 at% was defined. Owing to the presence of NiAl precipitates as observed by Atom Probe Tomography (APT), a lower bound of 3–5 at% Al was established. Within this concentration window, increasing the Al concentration gave rise to an increase in hardness by 225 HV due to an exceptionally high number density of 1025 NiAl precipitates per m3, as measured by APT. This work demonstrates the possibility of exploiting the IHT of the LMD process for the production of samples that are precipitation strengthened during the additive manufacturing process without need for any further heat treatment.
Subfields: Biomedical Engineering, Mechanical Engineering
View Paper: https://www.semanticscholar.org/paper/4bacf76cba030288da726dc8bf1f64ec042fbf13
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In Mechanical Engineering
Citations in the corpus
- Enhancing mechanical properties of wire + arc additively manufactured INCONEL 718 superalloy through in-process thermomechanical processing (2018, background): “In the as deposited condition, the microhardness generally remains a constant level from the top to the substrate despite the slightfluctuation, indicating a very sluggish response of IN718 to the intrinsic aging effect [23,24] from the layer-bylayer deposition process.”
- A review of the as-built SLM Ti-6Al-4V mechanical properties towards achieving fatigue resistant designs (2018, background): “Furthermore, taking advantage of the intrinsic heat treatment (IHT) of the AM fabrication process, which is associated with cyclic reheating of layers through continued layer deposition, there is the potential to induce precipitation growth in situ [2].”
- The influence of aging temperature and aging time on the mechanical and tribological properties of selective laser melted maraging 18Ni-300 steel (2018, background): “The enrichment of Ni stabilizes the retained austenite [30], and thereby allowing the detection of the austenite phase.”
- Microstructural characterization and properties of selective laser melted maraging steel with different build directions (2018, background): “Maraging steel (MS) is a special advanced highstrength steel developed in the 1960s, which combines ultra-high strength with good toughness and ductility [1,2].”