Investigation of Novel Post-Thermal Treatments of Alloy 718 Fabricated by Modulated Laser Powder Bed Fusion

Konstantinos Georgilas; Alessandro  Sergi; Raja H.U. Khan; Mehmet Kartal

doi:10.1016/j.msea.2022.143502

Investigation of Novel Post-Thermal Treatments of Alloy 718 Fabricated by Modulated Laser Powder Bed Fusion

Konstantinos Georgilas, Alessandro Sergi, Raja H.U. Khan, Mehmet Kartal^* (Corresponding Author)

^*Corresponding author for this work

Engineering

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

The aim of this work is to determine the impact of post-thermal treatments on the mechanical properties and microstructure of alloy 718 superalloy manufactured through modulated laser powder bed fusion. Three post-thermal treatments at 980°C and 1200°C with and without hot isostatic pressing are utilised, followed by standard ageing procedure. The tensile mechanical properties, microstructure, crystallography, morphology, fracture impact and hardness after each heat treatment are determined. It has been found that the heat treatment procedure at 980°C significantly affects the tensile properties while leading to no change in grain size or orientation, and formation of twined
grains. A temperature of 1200°C with and without pressure causes considerable grain growth in comparison with the as-built and 980 conditions and significant formation of twinned grains. Hot isostatic pressing was found to produce the tensile mechanical properties close to those of wrought alloy 718.

Original language	English
Article number	143502
Journal	Materials Science and Engineering A
DOIs	https://doi.org/10.1016/j.msea.2022.143502
Publication status	Accepted/In press - 22 Jun 2022

Keywords

Electron microscopy
Characterisation
Nickel alloys
Laser methods
Powder methods

Access to Document

10.1016/j.msea.2022.143502Licence: CC BY-NC-ND

Cite this

@article{6668c8775cd3406385f110bf4f50ad13,

title = "Investigation of Novel Post-Thermal Treatments of Alloy 718 Fabricated by Modulated Laser Powder Bed Fusion",

abstract = "The aim of this work is to determine the impact of post-thermal treatments on the mechanical properties and microstructure of alloy 718 superalloy manufactured through modulated laser powder bed fusion. Three post-thermal treatments at 980°C and 1200°C with and without hot isostatic pressing are utilised, followed by standard ageing procedure. The tensile mechanical properties, microstructure, crystallography, morphology, fracture impact and hardness after each heat treatment are determined. It has been found that the heat treatment procedure at 980°C significantly affects the tensile properties while leading to no change in grain size or orientation, and formation of twinedgrains. A temperature of 1200°C with and without pressure causes considerable grain growth in comparison with the as-built and 980 conditions and significant formation of twinned grains. Hot isostatic pressing was found to produce the tensile mechanical properties close to those of wrought alloy 718.",

keywords = "Electron microscopy, Characterisation, Nickel alloys, Laser methods, Powder methods",

author = "Konstantinos Georgilas and Alessandro Sergi and Khan, {Raja H.U.} and Mehmet Kartal",

note = "Acknowledgements This publication was made possible by the sponsorship and support of Lloyd{\textquoteright}s Register Foundation The work was enabled through, and undertaken at, the National Structural Integrity Research Centre (NSIRC), a postgraduate engineering facility for industry-led research into structural integrity established and managed by TWI through a network of both national and international Universities. Lloyd{\textquoteright}s Register Foundation helps to protect life and property by supporting engineering-related education, public engagement, and the application of research. ",

year = "2022",

month = jun,

day = "22",

doi = "10.1016/j.msea.2022.143502",

language = "English",

journal = "Materials Science and Engineering A",

issn = "0921-5093",

publisher = "Elsevier BV",

}

TY - JOUR

T1 - Investigation of Novel Post-Thermal Treatments of Alloy 718 Fabricated by Modulated Laser Powder Bed Fusion

AU - Georgilas, Konstantinos

AU - Sergi, Alessandro

AU - Khan, Raja H.U.

AU - Kartal, Mehmet

N1 - Acknowledgements This publication was made possible by the sponsorship and support of Lloyd’s Register Foundation The work was enabled through, and undertaken at, the National Structural Integrity Research Centre (NSIRC), a postgraduate engineering facility for industry-led research into structural integrity established and managed by TWI through a network of both national and international Universities. Lloyd’s Register Foundation helps to protect life and property by supporting engineering-related education, public engagement, and the application of research.

PY - 2022/6/22

Y1 - 2022/6/22

N2 - The aim of this work is to determine the impact of post-thermal treatments on the mechanical properties and microstructure of alloy 718 superalloy manufactured through modulated laser powder bed fusion. Three post-thermal treatments at 980°C and 1200°C with and without hot isostatic pressing are utilised, followed by standard ageing procedure. The tensile mechanical properties, microstructure, crystallography, morphology, fracture impact and hardness after each heat treatment are determined. It has been found that the heat treatment procedure at 980°C significantly affects the tensile properties while leading to no change in grain size or orientation, and formation of twinedgrains. A temperature of 1200°C with and without pressure causes considerable grain growth in comparison with the as-built and 980 conditions and significant formation of twinned grains. Hot isostatic pressing was found to produce the tensile mechanical properties close to those of wrought alloy 718.

AB - The aim of this work is to determine the impact of post-thermal treatments on the mechanical properties and microstructure of alloy 718 superalloy manufactured through modulated laser powder bed fusion. Three post-thermal treatments at 980°C and 1200°C with and without hot isostatic pressing are utilised, followed by standard ageing procedure. The tensile mechanical properties, microstructure, crystallography, morphology, fracture impact and hardness after each heat treatment are determined. It has been found that the heat treatment procedure at 980°C significantly affects the tensile properties while leading to no change in grain size or orientation, and formation of twinedgrains. A temperature of 1200°C with and without pressure causes considerable grain growth in comparison with the as-built and 980 conditions and significant formation of twinned grains. Hot isostatic pressing was found to produce the tensile mechanical properties close to those of wrought alloy 718.

KW - Electron microscopy

KW - Characterisation

KW - Nickel alloys

KW - Laser methods

KW - Powder methods

U2 - 10.1016/j.msea.2022.143502

DO - 10.1016/j.msea.2022.143502

M3 - Article

JO - Materials Science and Engineering A

JF - Materials Science and Engineering A

SN - 0921-5093

M1 - 143502

ER -

Investigation of Novel Post-Thermal Treatments of Alloy 718 Fabricated by Modulated Laser Powder Bed Fusion

Abstract

Keywords

Access to Document

Fingerprint

Cite this