Texture tailored through combination of molten pool morphology and scanning path in laser additive manufacturing of alloy 718

Abstract

Texture control is vital for the performance improvement of laser additive manufacturing parts. In the current manuscript, the effect of molten pool morphology and scanning path on texture have been studied for Inconel 718 sample fabricated by directed energy deposition (DED). The molten pool formed at a pulse period of 20 ms is shallower than that formed at a pulse period of 100 ms. The V-shaped grains (<110> // BD) are generated in the overlapping area for all samples. While Z-type grains (<110> // SD) are generated in the molten pool center for the sample with bidirectional scanning path at a pulse period of 20 ms. The unique texture with V-shaped grains (<110> // BD) in the overlapping area and Z-type grains (<110> // SD) in the molten pool center was firstly observed in the current manuscript. The value of Taylor factor of Z-type grains (<110> // SD) is larger than that of V-shaped grains (<110> // BD). Meanwhile, the effect of different heat treatments on the texture evolution was analyzed. This research provides a promising approach for texture customization, which can also increase the understanding of texture evolution.