Microstructural Evolution and Mechanical Properties in Dissimilar Laser Welding of Inconel 718 and PH 17-7
Journal of Materials Engineering and Performance, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s11665-026-14303-1
- Dergi Adı: Journal of Materials Engineering and Performance
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Chemical Abstracts Core, Compendex, INSPEC, Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: dissimilar joints, inconel 718, laser welding, laves phase, PH 17-7
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
This study investigates the microstructural evolution and mechanical performance of autogenous pulsed Nd: YAG laser-welded dissimilar joints between Inconel 718 and PH 17-7 precipitation-hardening stainless steel. Characterization via scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed that rapid solidification kinetics promote a morphological transition from columnar and cellular to equiaxed dendritic structures in the fusion zone. Although interdendritic microsegregation of Nb and Mo drove the precipitation of brittle Laves phases, the extreme cooling rates of the pulsed laser restricted these phases to a discrete, discontinuous morphology rather than a continuous network. This microstructural suppression preserved a strong strength-ductility synergy, yielding an ultimate tensile strength of ~ 800 MPa and > 20% elongation. Fractography confirmed mixed-mode failure localized within the weld metal, characterized by microvoid coalescence at the discrete Laves interfaces. Microhardness mapping demonstrated a uniform profile, interrupted by a localized hardness surge at the PH 17-7 fusion boundary attributed to untempered lath martensite and δ-ferrite formation. This work establishes autogenous pulsed laser welding as an effective methodology for synthesizing robust Inconel 718/PH 17-7 dissimilar joints by tailoring interfacial phase morphologies and microsegregation.