Laser powder bed fusion of GH4099 Ni-based superalloy under a static magnetic field with tailored microstructure and enhanced mechanical performance
Chaoyue Chen, Keqing Zhang, Ruixin Zhao, Songzhe Xu, Tao Hu, Xia Li, Xiaopeng Li, Linda Ke, Jiang Wang, Zhongming Ren
Abstract
In the present work, the static magnetic field (SMF) was applied in the L-PBF process of a typical γʹ strengthening Ni-based superalloy of GH4099 concerning the as-built and heat-treated conditions. The SMF during the L-PBF process can effectively refine the cellular str ucture, refine the grain size, promote the columnar to equiaxed transition (CET), and reduce the dislocation density. After the solution-aging procedure, the SMF samples exhibited a refined grain structure, suggesting that the tailored microstructure is inherited after the solution-aging treatment. The tensile test results show that by applying the SMF during the L-PBF process, the ductility can be notably improved on both building planes under the as-built and heat-treatment conditions, and the anisotropy along different directions can be reduced. It reveals that the SMF in L-PBF can be an effective method to modulate the microstructure and improve the comprehensive mechanical properties for γʹ strengthening Ni-based superalloys.