Investigation of hydrogen embrittlement resistance of as-printed and surface treated Inconel 718

• Main Author: Mohammad Faizal Bin Abdul Rahman
• Other Authors: Upadrasta Ramamurty
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/177836
• Institution: Nanyang Technological University

Additive manufacturing (AM) of metals has emerged as a promising method for producing intricate and complex structures with enhanced efficiency. Under this, Laser Beam Powder Bed Fusion is used to manufacture Inconel 718. This research investigates the tensile properties of AM Inconel 718 and delves into the effects of hydrogen charging on its mechanical properties. Tensile testing and microstructural analysis are employed to evaluate the strength, ductility, and fracture characteristics of Inconel 718. Furthermore, this research also touches on the effects of laser shock peening (LSP) on hydrogen charged samples, as supplementary work, aiming to evaluate its effectiveness in mitigating the adverse effects of hydrogen charging on Inconel 718. Preliminary findings reveal notable differences between the uncharged and hydrogen-charged samples. Uncharged Inconel 718 exhibits superior mechanical properties, with fewer cracks and increased ductility compared to the hydrogen-charged samples. Microstructural analysis using Scanning Electron Microscopy, indicates significant plastic deformation in uncharged samples, as shown by dimples on the fracture surface. In contrast, hydrogen charged samples display reduced ductility and increased crack formations, resulting in a flat and featureless surface. This is an indication of reduced plastic deformation. Overall, this research contributes to advancing the understanding of the mechanical behaviour of AM Inconel 718 and provides critical insights into the effects of hydrogen charging. By interpreting these aspects, this study offers valuable information for optimising the performance and reliability of AM-produced components in industrial applications.