Microstructure evolution-based design of thermal post-treatments for EBM-built Alloy 718

摘要: Alloy 718 samples were fabricated by electron beam melting (EBM) additive manufacturing process. The work focused on systematic investigation of response the material to various thermal post-treatments, involving hot isostatic pressing (HIPing), solution treatment (ST) and two-step aging, tailor post-treatment procedure for EBM-built 718. Results showed that HIPing at lowered temperature can be used attaining desired defect closure while preserving grain size. Subjecting ST, with or without prior HIPing, mainly caused precipitation δ phase boundaries decreasing extent precipitation. Moreover, results suggest utility could dictated need achieve a certain content, as typically targeted homogenization after ST had already been achieved through HIPing. Detailed microstructural evolution during subsequent aging significantly shortened (‘4 + 1’ h), compared ‘standard’ long (‘8 + 8’ h) traditionally developed conventionally produced 718, might realizable. These have significant techno-economic implications in designing tailored post-treatments