Microstructure, fatigue, and impact toughness properties of additively manufactured nickel alloy 718

Journal Article · Thu Aug 01 00:00:00 EDT 2019 · Additive Manufacturing

DOI:https://doi.org/10.1016/j.addma.2019.06.009· OSTI ID:1614867

Komarasamy, Mageshwari ^[1]; Shukla, Shivakant ^[2]; Williams, Sarah ^[2]; Kandasamy, Kumar ^[3]; Kelly, Shawn ^[3]; Mishra, Rajiv S. ^[2]

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1. BATTELLE (PACIFIC NW LAB)
2. University of North Texas
3. Oerlikon Metco

A complete understanding of processing-structure-property-performance relationship of additively manufactured (AM) components are critical from an application standpoint. Therefore, in the current investigation, a comprehensive microstructural characterization and mechanical properties (tensile, fatigue and impact toughness) evaluation of nickel alloy 718 AM by the laser powder bed fusion (L-PBF) technique have been performed. AM builds were made from powders manufactured via different atomization conditions. Although the standard post-heat treatment procedure led to the removal of severe interdendritic segregation both grain boundary and intra-grain precipitation of d phase occurred. Regardless of d phase presence, axial fatigue properties of both the AM builds were similar to design handbook wrought fatigue data. However, due to the d phase, impact toughness properties were comparable to the wrought material conditions that exhibited d phase. Fractured surfaces of Charpy impact samples exhibited crack propagation extensively along the boundaries decorated by d precipitates.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1614867
• Report Number(s): PNNL-SA-150627
• Journal Information: Additive Manufacturing, Vol. 28
• Country of Publication: United States
• Language: English