EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

This study is focused on in-situ alloying of Al0,8FeNiCr composition
by melting commercially available powders using the LMD process. To obtain
an equivalent composition, commercially available powders of 316L, Inconel
718, pure Chromium and Al2024 were selected and provided in 45-105μm
powder diameter range. The final composition contain also Nb, Mo and Ti
from the alloys used in this study, their cumulated atomic ration represent
less than 2,5%. The 316L, Inconel 718 and pure Chromium powder were
mixed to obtain the equimolar ratio of FeCrNi. The mix was
homogenized 30min in a tumbling machine and set a separated powder distributor.
The aluminium powder was set in a second powder distributor to
allow finer control on its mass rate. The substrate used was low carbon
steel, it was pre-heated to 200°C on a hot plate to avoid cracks during deposition.
The chemical composition and microstructure were investigated,
the chemical analysis shows higher Fe content (42,5 atomic%) in the coating
due to the mixing of materials with the substrate, the Al, Cr and Ni atomic
ratio were under the aimed atomic ratio (17,4 atomic %, 17,0 atomic% and
20,1 atomic % respectively). The element repartition is homogeneous in the
coating without showing a clustering effect. It appears that the Nb, Ti and Mo segregate at the grain boundary, forming intermetallics such as TiNb around
globular grain containing FeCr and AlNi phases. In conclusion, fully dense
coatings of HEA were obtained by in-situ alloying of commercially available
powders using the LMD process. The chemical composition obtained is modified
by the mixing of the substrate material with the deposited material, increasing
the iron atomic ratio.