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.
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 |
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Article number | 143502 |
Number of pages | 9 |
Journal | Materials Science and Engineering A |
Volume | 849 |
DOIs | |
Publication status | Published - 1 Aug 2022 |
Bibliographical note
AcknowledgementsThis 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.
Keywords
- Electron microscopy
- Characterisation
- Nickel alloys
- Laser methods
- Powder methods