2026-10-06T19:25:11Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34001730 2026-09-26T03:08:06Z category_26734 category_26650 item_type_3 month_year_09_2026

<b>Flat-top laser powder bed fusion of non-weldable Ni-based superalloy: crack mitigation through microstructural engineering for enhanced mechanical properties</b> Ruixin Zhao (25112637) Linghuan HE (25112671) Jianan Cai (25112673) Yuyang Hou (25112675) Songzhe Xu (25112678) Jiang Wang (25112680) Tao Yang (23695761) Chaoyue Chen (25112683) Zhongming Ren (25112685) Metals and alloy materials Additive manufacturing Laser powder bed fusion Non-weldable superalloy Flat-top laser beam Solidification microstructure Mechanical properties <p dir="ltr">Laser powder bed fusion (L-PBF) of high-γ′ Ni-based superalloys is limited by cracking and microstructural heterogeneity. Here, a flat top (FT) laser beam was used to fabricate Inconel 939, and its cracking behavior, microstructure, and tensile properties were compared with those produced by a Gaussian beam. At 850 W and 350 mm/s, FT-LPBF produced specimens with 99.95% relative density and no cracks detected in the examined sections. Compared with the Gaussian conditions, FT processing generated flatter melt pools, continuous columnar grains, and a lower fraction of high-angle grain boundaries. The as-built FT specimen achieved an ultimate tensile strength (UTS) of 1211 MPa and elongation of 18.8% at room temperature. From 800 to 1000℃, Its UTS decreased from 983 to 284 MPa, while elongation increased from 18.4% to 29.4%. Thermal-fluid simulations suggest that a more uniform temperature field and reduced lateral thermal gradients contribute to stable epitaxial growth. These findings demonstrate that a more uniformly distributed laser beam profile can improve the printablility and tensile performance of IN939 without post-processing.</p> 2026-09-26T03:08:06Z Dataset Dataset 10.6084/m9.figshare.34001730.v1 https://figshare.com/articles/dataset/_b_Flat-top_laser_powder_bed_fusion_of_non-weldable_Ni-based_superalloy_crack_mitigation_through_microstructural_engineering_for_enhanced_mechanical_properties_b_/34001730 CC BY 4.0