Strategies for high-quality fabrication of Inconel 625 parts via powder bed fusion–laser beam

Additive manufacturing, particularly powder bed fusion–laser beam (PBF–LB) technology, offers new opportunities for fabricating complex alloy components with
enhanced design flexibility. Specifically, Inconel 625 (IN625), a nickel-based superalloy, is widely used in high-performance applications because of its excellent mechanical properties and corrosion resistance. However, the quality of PBF–LB-manufactured parts is highly sensitive to process parameters, especially the volumetric energy density (VED). This study investigated the effects of laser power (P) and scan speed (v) on the quality of IN625 samples produced via PBF–LB. A total of 60 samples were fabricated across three build plate rotation angles (0°, 90°, and 180°) and evaluated for porosity, surface morphology, and microhardness, revealing a clear correlation between VED and key quality metrics. Optimal material properties were achieved within a VED range of 66–100 J/mm3, whereas deviations from this range led to defects such as a lack-of-fusion, keyholing, and balling. Additionally, maintaining a balanced relationship between P and v while keeping the other parameters constant was found to be essential for proper melting and defect mitigation. The results further indicate that, under the tested conditions, the rotation of the build plate and the position of the specimen have no significant influence on the quality or properties of
the part. Overall, the findings highlight the critical role of process parameter control in producing dense, defect-minimized IN625 parts via PBF–LB.