<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Understanding the effect of powder feedstock alterations during multicycle additive manufacturing on the quality of built components is crucial to meet the requirements on critical parts for aerospace engine applications. In this study, powder recycling of Alloy 718 during electron beam melting was studied to understand its influence on fracture behavior of Charpy impact test bars. High resolution scanning electron microscopy was employed for fracture surface analysis on test bars produced from virgin and recycled powder. For all investigated samples, an intergranular type of fracture, initiated by non-metallic phases and bonding defects, was typically observed in the regions close to or within the contour zone. The fracture mode in the bulk of the samples was mainly moderately ductile dimple fracture. The results show a clear correlation between powder degradation during multi-cycle powder reuse and the amount of damage relevant defects observed on the fracture surfaces. In particular, samples produced from recycled powder show a significant amount of aluminum-rich oxide defects, originating from aluminum-rich oxide particulates on the surface of the recycled powder.</p></abstract>

Understanding the effect of powder feedstock alterations during multicycle additive manufacturing on the quality of built components is crucial to meet the requirements on critical parts for aerospace engine applications. In this study, powder recycling of Alloy 718 during electron beam melting was studied to understand its influence on fracture behavior of Charpy impact test bars. High resolution scanning electron microscopy was employed for fracture surface analysis on test bars produced from virgin and recycled powder. For all investigated samples, an intergranular type of fracture, initiated by non-metallic phases and bonding defects, was typically observed in the regions close to or within the contour zone. The fracture mode in the bulk of the samples was mainly moderately ductile dimple fracture. The results show a clear correlation between powder degradation during multi-cycle powder reuse and the amount of damage relevant defects observed on the fracture surfaces. In particular, samples produced from recycled powder show a significant amount of aluminum-rich oxide defects, originating from aluminum-rich oxide particulates on the surface of the recycled powder.

Effect of Powder Recycling on the Fracture Behavior of Electron Beam Melted Alloy 718

Department of Industrial and Materials Science, Division of Materials and Manufacture

Department of Engineering Science, Additive Manufacturing Group

Powder Metallurgy Progress

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Understanding the effect of powder feedstock alterations during multicycle additive manufacturing on the quality of built components is crucial to meet the...

Effect of Powder Recycling on the Fracture Behavior of Electron Beam Melted Alloy 718

Published Online: Jul 25, 2018

Page range: 40 - 48

DOI: https://doi.org/10.1515/pmp-2018-0005

Keywords
additive manufacturing of Alloy 718, electron beam melting, powder recycling, powder degradation, fractography of AM components

© 2018 H. Gruber et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Effect of Powder Recycling on the Fracture Behavior of Electron Beam Melted Alloy 718

Published Online: Jul 25, 2018

Page range: 40 - 48

DOI: https://doi.org/10.1515/pmp-2018-0005

Keywordsadditive manufacturing of Alloy 718, electron beam melting, powder recycling, powder degradation, fractography of AM components

© 2018 H. Gruber et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
additive manufacturing of Alloy 718, electron beam melting, powder recycling, powder degradation, fractography of AM components