Densification Behavior and Build Quality of Duplex Stainless Steel Fabricated by Laser Powder Bed Fusion

A systematic study on the densification behavior and build quality of 2205 duplex stainless steel fabricated using laser powder bed fusion (LPBF) was performed by experiment and simulation, aiming to offer some supplementary work for research on additive manufacturing (AM) of duplex stainless steel. In this study, samples with differing laser powers were prepared, and a highest relative density of 98.87% was obtained. Then, the pore defects and surface morphologies were investigated to unveil densification behaviors during a building process. The relationship between surface morphologies and the formation of pores was discussed. It reveals that the inter-layer printing on these surface defects caused by unreasonable laser power could increase the possibility of inside pore defects and reduce the density of specimens. Particularly, the big spatters could be the cause of lack-of-fusion defects even under sufficient power input. Therefore, adequate intra- and inter-layer bonding under reasonable processing parameters is crucial for densification. The mechanical properties of the specimens prepared with the laser power of 260 W are the highest, and the yield strength, tensile strength, and elongation are 798.68 MPa, 953.63 MPa, and 10.85%, respectively.