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Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities

Products produced by additive manufacturing (AM) seek to exploit net shape manufacturing by eliminating or minimizing post-process stages such as machining. However, many applications which include turbo machinery components with tight dimensional tolerances and a smooth surface finish will require...

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Autores principales: Wood, Paul, Díaz-Álvarez, Antonio, Díaz-Álvarez, José, Miguélez, María Henar, Rusinek, Alexis, Gunputh, Urvashi F., Williams, Gavin, Bahi, Slim, Sienkiewicz, Judyta, Płatek, Paweł
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7765512/
https://www.ncbi.nlm.nih.gov/pubmed/33334067
http://dx.doi.org/10.3390/ma13245730
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author Wood, Paul
Díaz-Álvarez, Antonio
Díaz-Álvarez, José
Miguélez, María Henar
Rusinek, Alexis
Gunputh, Urvashi F.
Williams, Gavin
Bahi, Slim
Sienkiewicz, Judyta
Płatek, Paweł
author_facet Wood, Paul
Díaz-Álvarez, Antonio
Díaz-Álvarez, José
Miguélez, María Henar
Rusinek, Alexis
Gunputh, Urvashi F.
Williams, Gavin
Bahi, Slim
Sienkiewicz, Judyta
Płatek, Paweł
author_sort Wood, Paul
collection PubMed
description Products produced by additive manufacturing (AM) seek to exploit net shape manufacturing by eliminating or minimizing post-process stages such as machining. However, many applications which include turbo machinery components with tight dimensional tolerances and a smooth surface finish will require at least a light machine finishing stage. This paper investigates the machinability of the additively fabricated INCONEL718 (IN718) alloy produced by laser melting powder bed fusion (LM-PBF) with different levels of spherical porosity in the microstructure. The literature suggests that the band width for laser energy density, which combines the various scan process parameters to obtain a low spherical type porosity in the LM-PBF IN718 alloy (~1%), has wide breadth. With the increasing laser energy density and above a threshold, there is a rapid increase in the spherical pore size. In this paper, three tube samples each with different levels of spherical porosity were fabricated by varying the laser energy density for LM-PBF of the IN718 alloy within the stable and higher energy density range and the porosity measured. A low laser energy density was avoided due to balling up, which promotes highly irregular lack of fusion defects and poor consolidation within the alloy microstructure. An orthogonal turning test instrumented, with a three-component dynamometer to measure the cutting forces, was performed on AM produced IN718 tube samples under light cut conditions to simulate a finish machining process. The orthogonal turning tests were also performed on a tube sample obtained from the wrought extruded stock. The machining process parameters, which were studied include varying the cutting speed at three levels, at a fixed feed and under dry cut conditions for a short duration to avoid the tool wear. The results obtained were discussed and a notable finding was the higher rate of built-up-edge formation on the tool tip from the AM samples with a higher porosity and especially at a higher cutting speed. The paper also discusses the mechanisms that underpin the findings.
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spelling pubmed-77655122020-12-27 Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities Wood, Paul Díaz-Álvarez, Antonio Díaz-Álvarez, José Miguélez, María Henar Rusinek, Alexis Gunputh, Urvashi F. Williams, Gavin Bahi, Slim Sienkiewicz, Judyta Płatek, Paweł Materials (Basel) Article Products produced by additive manufacturing (AM) seek to exploit net shape manufacturing by eliminating or minimizing post-process stages such as machining. However, many applications which include turbo machinery components with tight dimensional tolerances and a smooth surface finish will require at least a light machine finishing stage. This paper investigates the machinability of the additively fabricated INCONEL718 (IN718) alloy produced by laser melting powder bed fusion (LM-PBF) with different levels of spherical porosity in the microstructure. The literature suggests that the band width for laser energy density, which combines the various scan process parameters to obtain a low spherical type porosity in the LM-PBF IN718 alloy (~1%), has wide breadth. With the increasing laser energy density and above a threshold, there is a rapid increase in the spherical pore size. In this paper, three tube samples each with different levels of spherical porosity were fabricated by varying the laser energy density for LM-PBF of the IN718 alloy within the stable and higher energy density range and the porosity measured. A low laser energy density was avoided due to balling up, which promotes highly irregular lack of fusion defects and poor consolidation within the alloy microstructure. An orthogonal turning test instrumented, with a three-component dynamometer to measure the cutting forces, was performed on AM produced IN718 tube samples under light cut conditions to simulate a finish machining process. The orthogonal turning tests were also performed on a tube sample obtained from the wrought extruded stock. The machining process parameters, which were studied include varying the cutting speed at three levels, at a fixed feed and under dry cut conditions for a short duration to avoid the tool wear. The results obtained were discussed and a notable finding was the higher rate of built-up-edge formation on the tool tip from the AM samples with a higher porosity and especially at a higher cutting speed. The paper also discusses the mechanisms that underpin the findings. MDPI 2020-12-15 /pmc/articles/PMC7765512/ /pubmed/33334067 http://dx.doi.org/10.3390/ma13245730 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Wood, Paul
Díaz-Álvarez, Antonio
Díaz-Álvarez, José
Miguélez, María Henar
Rusinek, Alexis
Gunputh, Urvashi F.
Williams, Gavin
Bahi, Slim
Sienkiewicz, Judyta
Płatek, Paweł
Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
title Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
title_full Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
title_fullStr Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
title_full_unstemmed Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
title_short Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
title_sort machinability of inconel718 alloy with a porous microstructure produced by laser melting powder bed fusion at higher energy densities
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7765512/
https://www.ncbi.nlm.nih.gov/pubmed/33334067
http://dx.doi.org/10.3390/ma13245730
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