Abstract
Post-heat treatment is a necessary and important step for additive-manufactured products to relieve residual stress and to further improve mechanical performance. In this work, the heat treatment strategy for Inconel 718 superalloy fabricated by rolling-assisted laser-directed energy deposition (L-DED) has been designed and systematically investigated for the first time. The results show that the designed homogenization heat treatment at 1080 °C for 10 min can effectively dissolve most of the detrimental Lave phases existing in the rolling-assisted L-DED samples. Meanwhile, it results in a homogenous grain structure through static recrystallization, while maintaining a similar prior-refined grain size of ∼8 µm. On this basis, a high number density of γ″ and γ′ precipitates appear in the microstructure after applying a subsequent double-aging heat treatment. The optimized microstructure through such effective post-heat treatment designed in this work has led to a significant increase in material strength at both the room and elevated temperatures while maintaining good ductility.
Original language | English |
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Pages (from-to) | 118-127 |
Number of pages | 10 |
Journal | Journal of Materials Science and Technology |
Volume | 144 |
DOIs | |
Publication status | Published - 1 May 2023 |
Keywords
- Additive manufacturing
- Heat treatment
- In-situ rolling
- Mechanical properties
- Nickel superalloy
Equipment
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Centre for Additive Manufacturing (MCAM)
Aijun Huang (Manager)
Materials Science & EngineeringFacility/equipment: Facility
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Centre for Electron Microscopy (MCEM)
Sorrell, F. (Manager) & Miller, P. (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility
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