Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness
Abstract
:1. Introduction
2. Materials and Experimental Methods
3. Results and Discussions
3.1. Microstructure
3.1.1. Effects of Solid Solution Heat Treatment
Annealing Twins in STA Samples
3.1.2. Effects of Aging
Solid Solution and Aging Heat Treatments (STA)
Direct Aging (DA)
3.2. Phase Identification with X-ray Diffraction
3.3. Vickers Hardness Measurement
4. Conclusions
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Element | Ni | Cr | Fe | Nb | Mo | Ti | Al | Co | Mn | Si | Cu | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
wt. % | Min | 50 | 17 | 11 | 4.8 | 2.8 | 0.7 | 0.2 | - | - | - | - |
Max | 55 | 21 | 22.4 | 5.5 | 3.3 | 1.2 | 0.8 | 1 | 0.4 | 0.4 | 0.3 |
Specimen | Solid Solution Heat Treatment | Precipitation Hardening | ||||||
---|---|---|---|---|---|---|---|---|
T (°C) | Hold Time (h) | Cooling | 1st Aging | 2nd Aging | Cooling | |||
T (°C) | Time (h) | T (°C) | Time (h) | |||||
ST1 | 1100 | 1 | quenched in cold water (16–18 °C) | |||||
ST3 | 3 | |||||||
ST6 | 6 | |||||||
ST9 | 9 | |||||||
ST16 | 16 | |||||||
ST24 | 24 | |||||||
STA1 | 1 | 760 | 10 | 650 | 10 | air cooled | ||
STA3 | 3 | |||||||
STA6 | 6 | |||||||
STA9 | 9 | |||||||
STA16 | 16 | |||||||
STA24 | 24 | |||||||
DA | Direct aged | |||||||
AP | As-printed (not heat treated) |
Scheme | Hardness [HV] | |||
---|---|---|---|---|
AP | ST | STA | %ΔHV | |
AP | 308 ± 5 | |||
DA | 446 ± 4 | 45 | ||
1 h | 249 ± 4 | 456 ± 4 | 49 | |
3 h | 200 ± 3 | 444 ± 5 | 45 | |
6 h | 195 ± 3 | 439 ± 3 | 43 | |
9 h | 191 ± 3 | 442 ± 6 | 44 | |
16 h | 192 ± 3 | 439 ± 3 | 43 | |
24 h | 192 ± 5 | 420 ± 5 | 36 |
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Tucho, W.M.; Hansen, V. Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness. Metals 2021, 11, 266. https://doi.org/10.3390/met11020266
Tucho WM, Hansen V. Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness. Metals. 2021; 11(2):266. https://doi.org/10.3390/met11020266
Chicago/Turabian StyleTucho, Wakshum M., and Vidar Hansen. 2021. "Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness" Metals 11, no. 2: 266. https://doi.org/10.3390/met11020266