Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics
Low-frequency pulsed laser beam welding (PLBW) was employed in building 0.32 mm-thick Inconel 718 superalloy butt joints which are frequently applied in manufacturing high-temperature functional units in the aviation industry. Several process parameter combinations concerning peak laser power, weldi...
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| Format: | Article |
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Elsevier
2023-11-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S223878542302759X |
| _version_ | 1797301481458630656 |
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| author | Jicheng Chen Yiting Chang Yanhong Wei |
| author_facet | Jicheng Chen Yiting Chang Yanhong Wei |
| author_sort | Jicheng Chen |
| collection | DOAJ |
| description | Low-frequency pulsed laser beam welding (PLBW) was employed in building 0.32 mm-thick Inconel 718 superalloy butt joints which are frequently applied in manufacturing high-temperature functional units in the aviation industry. Several process parameter combinations concerning peak laser power, welding speed, and pulse frequency were implemented to explore the macro morphology, microstructure, and mechanical properties of the welded joints. Examinations exhibit that the resulting weld beads possess high continuity at the surface with an overlap factor ranging from 0.58 to 0.73. The cross-sectional profile changes from a V-shape to an H-shape with increasing heat input. Finer grain structures composed of γ matrix and γ/Laves eutectic penetration are observed within the FZ center, as compared to that near the fusion line. Excellent performance is achieved in microhardness and tensile tests. Numerical simulation based on an integrated mathematic model reveals periodic keyhole and weld pool dynamics depending on the pulsing laser power. During a typical pulse interval, keyhole geometry collapses within a fraction of a millisecond, leading to a sharp cooling stage at ∼4 × 106 K/s, and then, the melt cools due to the thermal convection with a normal cooling rate of 105 K/s. The full growth of the adjacent weld spot results in the secondary melting zone (SMZ), wherein the columnar dendrites can be refined mainly due to the heterogeneous nucleation as compared to the primary melting zone (PMZ). |
| first_indexed | 2024-03-07T23:23:12Z |
| format | Article |
| id | doaj.art-c491e70429834d9ca1fbad60ea984b8a |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-07T23:23:12Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
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| series | Journal of Materials Research and Technology |
| spelling | doaj.art-c491e70429834d9ca1fbad60ea984b8a2024-02-21T05:27:20ZengElsevierJournal of Materials Research and Technology2238-78542023-11-012741454156Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristicsJicheng Chen0Yiting Chang1Yanhong Wei2College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China; Institute of Advanced Joining and Repairing Technology, Wuxi Research Institute, Nanjing University of Aeronautics and Astronautic, Wuxi, 214100, China; Corresponding author. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, ChinaCollege of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China; Institute of Advanced Joining and Repairing Technology, Wuxi Research Institute, Nanjing University of Aeronautics and Astronautic, Wuxi, 214100, ChinaLow-frequency pulsed laser beam welding (PLBW) was employed in building 0.32 mm-thick Inconel 718 superalloy butt joints which are frequently applied in manufacturing high-temperature functional units in the aviation industry. Several process parameter combinations concerning peak laser power, welding speed, and pulse frequency were implemented to explore the macro morphology, microstructure, and mechanical properties of the welded joints. Examinations exhibit that the resulting weld beads possess high continuity at the surface with an overlap factor ranging from 0.58 to 0.73. The cross-sectional profile changes from a V-shape to an H-shape with increasing heat input. Finer grain structures composed of γ matrix and γ/Laves eutectic penetration are observed within the FZ center, as compared to that near the fusion line. Excellent performance is achieved in microhardness and tensile tests. Numerical simulation based on an integrated mathematic model reveals periodic keyhole and weld pool dynamics depending on the pulsing laser power. During a typical pulse interval, keyhole geometry collapses within a fraction of a millisecond, leading to a sharp cooling stage at ∼4 × 106 K/s, and then, the melt cools due to the thermal convection with a normal cooling rate of 105 K/s. The full growth of the adjacent weld spot results in the secondary melting zone (SMZ), wherein the columnar dendrites can be refined mainly due to the heterogeneous nucleation as compared to the primary melting zone (PMZ).http://www.sciencedirect.com/science/article/pii/S223878542302759XUltra-thin Inconel 718 sheetPulse wave laser beam weldingOverlap factorPeriodic dynamic evolutionsGrain refinement |
| spellingShingle | Jicheng Chen Yiting Chang Yanhong Wei Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics Journal of Materials Research and Technology Ultra-thin Inconel 718 sheet Pulse wave laser beam welding Overlap factor Periodic dynamic evolutions Grain refinement |
| title | Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics |
| title_full | Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics |
| title_fullStr | Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics |
| title_full_unstemmed | Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics |
| title_short | Building ultra-thin Inconel 718 sheet joints using low-frequency PLBW scheme: Weld bead quality, keyhole dynamics, and solidification characteristics |
| title_sort | building ultra thin inconel 718 sheet joints using low frequency plbw scheme weld bead quality keyhole dynamics and solidification characteristics |
| topic | Ultra-thin Inconel 718 sheet Pulse wave laser beam welding Overlap factor Periodic dynamic evolutions Grain refinement |
| url | http://www.sciencedirect.com/science/article/pii/S223878542302759X |
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