20.500.12556/DiRROS-22868 Influence of laser beam shape and post heat-treatment on the microstructure and mechanical properties of nickel-based alloy IN718 manufactured by laser powder bed fusion This study examines the effect of Gaussian and ring-shaped laser beam profiles on the microstructural development and mechanical properties of the PBF-LB/M processed nickel-based alloy Inconel 718 in its as-built and post-heat-treated conditions. Beam shaping was employed to achieve a faster build rate without compromising material properties. One of the objectives was to optimise heat treatment conditions for the beam-shaped profile. The post-heat-treatment process included four different solution annealing temperatures (954 °C, 984 °C, 1034 °C and 1154 °C), followed by two-step ageing, respectively. The microstructure evolution was revealed using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray diffraction (EDS). The mechanical properties in all investigated conditions were evaluated based on tensile tests at room temperature. Using a Gaussian laser beam profile results in a fine-grained microstructure without a strong columnar orientation, while the ring beam profile produces a distinct columnar structure with larger nanodendritic grains and dislocation cells. Both beam profiles exhibit a similar proportion of Laves phase. After post-heat treatment, the Gaussian beam profile generally provides 3-7 % higher mechanical properties. The differences in mechanical properties between horizontal and vertical building directions are greater for ring-shaped laser beam profiles. Heat-treatment temperature above 1034 °C leads to recrystallisation, grain growth and the formation of carbonitrides which reduce mechanical properties. Based on the results, the proposed optimal heat-treatment temperature for both investigated laser beam shapes is 984 °C. At this temperature, tensile strength equalises between horizontal and vertical build directions while yield strength increases, which is beneficial for most applications. PBF-LB/M beam shaping IN718 heat treatment mechanical properties true false true Elsevier Nizozemska Angleški jezik Ni določen © 2025 The Authors Neznano 2025-07-07 11:10:19 2025-07-07 11:10:20 2025-10-24 03:52:24 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne 19. 6. 2025; str. 1970-1986 Vol. 37 Jul.-Aug. 2025 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2025-07-01 620.1:669.245 2214-0697 10.1016/j.jmrt.2025.06.119 239937283 RAZ_Godec_Matjaz_2025.pdf RAZ_Godec_Matjaz_2025.pdf 1 E04183F26EA6A1EB1ED311D77EDA2FE2 8512ff76ddbb53602d1eae7904265c7863f4f85b212af0d8ad5ae0614a8b45af f2ba1e64-5b12-11f0-8080-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=33281 https://www.sciencedirect.com/science/article/pii/S2238785425015418?via%3Dihub 1 35afc466-5b12-11f0-8080-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=33280 Inštitut za kovinske materiale in tehnologije 0 0 0