Additively manufactured Haynes-282 monoliths containing thin wall struts of varying thicknesses
Bryan Lim, Hansheng Chen, Keita Nomoto, Zibin Chen, Alec I. Saville, Sven C. Vogel, Amy J. Clarke, Anna Paradowska, Mark Reid, Sophie Primig, Xiaozhou Liao, S. S. Babu, Andrew Breen, Simon P. Ringer
Abstract
Magnitude and distribution of residual stresses in additively manufactured Ni-based superalloys may impact the mechanical performance of as-fabricated parts. Though electron beam powder bed fusion (E-PBF) can produce components with minimal defects and residual stresses compared to laser powder bed fusion and directed energy deposition, variations of them may occur within the complex geometry of a component, due to inherent variations of thermal signatures and the evolution of section modulus along the build direction. This work reveals the residual stress distribution, characterised from neutron diffraction, of an as-fabricated Haynes 282 monolith containing internal cube voids and thin wall struts of varying thicknesses. Complementary local hardness measurements and multi-scale microscopy were used to investigate the geometry-structure-property relationships. Observed variations in hardness were attributed to a combination of type I macro-scale residual stresses and variations in bimodal γ′ precipitation behaviour. The results highlight the influence of residual stresses and microstructure on the mechanical properties of E-PBF Haynes 282.