Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions
Linear friction welding (LFW) is a near net shape solid state joining technology for aerospace applications. In this study LFW of a recently introduced Ni-based superalloy, AD730™, with superior properties for use in the hot section of gas turbines was studied. In order to minimize the number of exp...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2019-12-01
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| Series: | Materials & Design |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127519305556 |
| _version_ | 1818137711445278720 |
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| author | F. Masoumi D. Shahriari H. Monajati J. Cormier B.C.D. Flipo A. Devaux M. Jahazi |
| author_facet | F. Masoumi D. Shahriari H. Monajati J. Cormier B.C.D. Flipo A. Devaux M. Jahazi |
| author_sort | F. Masoumi |
| collection | DOAJ |
| description | Linear friction welding (LFW) is a near net shape solid state joining technology for aerospace applications. In this study LFW of a recently introduced Ni-based superalloy, AD730™, with superior properties for use in the hot section of gas turbines was studied. In order to minimize the number of experiments for achieving sound welds, an analytical method was developed that allowed to determine the optimum process parameters with a limited number of experiments. The predictions of the method were validated by LFW experiments, and sound samples without defects were produced. Microstructure evolution of the as-welded samples from the weld center to the base metal was investigated using laser confocal and field emission scanning electron microscopy (SEM) including electron back scatter diffraction (EBSD), energy dispersive spectrometer (EDS) and backscattered imaging (BSE). Post-weld heat treatment (PWHT), consisting of a γ′ sub-solvus solutionizing followed by aging, was conducted on LFWed blocks. Then, microstructure evolution and mechanical testing were conducted on PWHTed samples and compared with the as welded blocks. The obtained results were correlated with microhardness as well as tensile testing at room temperature and 650 °C, and interpreted in terms of fundamental metallurgical processes. Macroscopic examination of the PWHTed joints revealed that the samples failed out of the weld zone, further demonstrating the appropriate selection of LFW processing parameters using the proposed analytical method. PWHTed samples exhibited better room and high temperature tensile properties compared to those of the as-welded samples. Microscopic examination of the fracture zones of the samples showed that the higher levels of reprecipitation of γ′ particles in the thermomechanically-affected zone (TMAZ) of the PWHT samples were associated to their higher tensile properties compared to the as welded ones. Keywords: AD730™ Ni-base superalloy, Linear friction welding, Process parameter, Analytical method, Microstructure, Mechanical property |
| first_indexed | 2024-12-11T10:00:39Z |
| format | Article |
| id | doaj.art-759c13b15ad54ee99209dbbdf5730d30 |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-12-11T10:00:39Z |
| publishDate | 2019-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-759c13b15ad54ee99209dbbdf5730d302022-12-22T01:12:08ZengElsevierMaterials & Design0264-12752019-12-01183Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactionsF. Masoumi0D. Shahriari1H. Monajati2J. Cormier3B.C.D. Flipo4A. Devaux5M. Jahazi6Department of Mechanical Engineering, École de Technologie Supérieure (ÉTS), Montreal, QC H3C 1K3, Canada; Corresponding author.Department of Mechanical Engineering, École de Technologie Supérieure (ÉTS), Montreal, QC H3C 1K3, CanadaDepartment of Mechanical Engineering, École de Technologie Supérieure (ÉTS), Montreal, QC H3C 1K3, CanadaInstitute Pprime, UPR CNRS 3346, Physics and Mechanics of Materials Department, ISAE, ENSMA, BP 40109, Futuroscope, Chasseneuil Cedex 86961, FranceTWI Ltd, Granta Park, Great Abington, Cambridge CB21 6AL, UKAubert & Duval, Site des Ancizes, BP1, 63770 Les Ancizes Cedex, FranceDepartment of Mechanical Engineering, École de Technologie Supérieure (ÉTS), Montreal, QC H3C 1K3, Canada; Corresponding author.Linear friction welding (LFW) is a near net shape solid state joining technology for aerospace applications. In this study LFW of a recently introduced Ni-based superalloy, AD730™, with superior properties for use in the hot section of gas turbines was studied. In order to minimize the number of experiments for achieving sound welds, an analytical method was developed that allowed to determine the optimum process parameters with a limited number of experiments. The predictions of the method were validated by LFW experiments, and sound samples without defects were produced. Microstructure evolution of the as-welded samples from the weld center to the base metal was investigated using laser confocal and field emission scanning electron microscopy (SEM) including electron back scatter diffraction (EBSD), energy dispersive spectrometer (EDS) and backscattered imaging (BSE). Post-weld heat treatment (PWHT), consisting of a γ′ sub-solvus solutionizing followed by aging, was conducted on LFWed blocks. Then, microstructure evolution and mechanical testing were conducted on PWHTed samples and compared with the as welded blocks. The obtained results were correlated with microhardness as well as tensile testing at room temperature and 650 °C, and interpreted in terms of fundamental metallurgical processes. Macroscopic examination of the PWHTed joints revealed that the samples failed out of the weld zone, further demonstrating the appropriate selection of LFW processing parameters using the proposed analytical method. PWHTed samples exhibited better room and high temperature tensile properties compared to those of the as-welded samples. Microscopic examination of the fracture zones of the samples showed that the higher levels of reprecipitation of γ′ particles in the thermomechanically-affected zone (TMAZ) of the PWHT samples were associated to their higher tensile properties compared to the as welded ones. Keywords: AD730™ Ni-base superalloy, Linear friction welding, Process parameter, Analytical method, Microstructure, Mechanical propertyhttp://www.sciencedirect.com/science/article/pii/S0264127519305556 |
| spellingShingle | F. Masoumi D. Shahriari H. Monajati J. Cormier B.C.D. Flipo A. Devaux M. Jahazi Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions Materials & Design |
| title | Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions |
| title_full | Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions |
| title_fullStr | Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions |
| title_full_unstemmed | Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions |
| title_short | Linear friction welding of AD730™ Ni-base superalloy: Process-microstructure-property interactions |
| title_sort | linear friction welding of ad730™ ni base superalloy process microstructure property interactions |
| url | http://www.sciencedirect.com/science/article/pii/S0264127519305556 |
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