Effect of deposition modes on electron beam directed energy deposited inconel 718

Abstract

Inconel 718 thin walls were fabricated via electron beam directed energy deposition (EB-EDE) to investigated their microstructure and mechanical properties in terms of the deposition modes. Results revealed that the deposition modes had great effects on the microstructural evolution and thus influenced the mechanical properties. The layered nature and the fine dendrites were produced by the intermittent deposition, while the coarse and irregular cellular crystals were formed under the continuous deposition. The harmful Laves phase was precipitated under both deposition modes. The microhardness and tensile strength of the build-ups deposited intermittently were higher because there were fewer Laves phase. This work provided a new perspective to explain the microstructure differences of multi-layered components formed by EB-DED.