Additional Phases at High Boron Content in High-Temperature Co–Re–Cr Alloys
Abstract
:1. Introduction
2. Materials and Methods
2.1. In-Situ Thermal Cycle during Neutron Diffraction Measurement
2.2. SEM and EDS
3. Results
3.1. Neutron Diffraction Measurements at RT
3.2. Neutron Diffraction Measurements at HT
3.3. SEM and EDS
3.4. Parameters Summary
4. Discussion
4.1. Appearance of Additional Hexagonal Phases
4.2. Background Intensity
4.3. Explanation of the Formation of New Phases
4.4. Identification of Phases
4.5. Boron Influence
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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EDS Region 2 | EDS Spot 3 | Composition (at %) | Average Atomic Radius rhcp (Å) | hcp Lattice Parameters Calculated 4 | Phase | hcp Lattice Parameters Measured 5 | Density Calculated (g/cm3) | Incoherent Scat. 6 (cm−1) | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Co | Re | Cr | ahcpi (Å) | chcpi (Å) | a (Å) | c (Å) | ||||||
center | 1 and 3 in Figure 6a | 61.6 | 17.5 | 20.9 | 1.3309 | - 1 | - 1 | hcp-1 | 2.5631 (2) | 4.1321 (3) | 11.27 | 0.364 |
outer layer | 1 and 2 in Figure 6b | 23.5 | 73.8 | 2.7 | 1.4480 | 2.6925 | 4.3439 | hcp-2 | 2.6928 (4) | 4.326 (1) | 18.98 | 0.211 |
near surface zone | 3 and 4 in Figure 6b | 53.2 | 37.8 | 9.0 | 1.3662 | 2.6021 | 4.1960 | hcp-3 | 2.606 (1) | 4.213 (3) | 14.26 | 0.350 |
Sample | Phase | Volume Fraction at RT before In-Situ Treatment (%) | Volume Fraction at 1500 (500 ppm B) or 1490 °C (1000 ppm B) (%) | Volume Fraction at RT after In-Situ Treatment (%) |
---|---|---|---|---|
500 ppm B | hcp-1 | 98(0.6)% | 34(0.7)% | 90(0.7)% |
hcp-2 | - | 12(0.7)% | 4.6(0.4)% | |
fcc | - | 52(0.7)% | - | |
σ | 2(0.3)% | 2(0.5)% | 5.4(0.4)% | |
1000 ppm B | hcp-1 | 96.3(0.6)% | (1.2)53.8% | 62.2(1.4)% |
hcp-2 | - | 0% 1 | 12.9(0.5)% | |
hcp-3 | - | 34.6(1.1)% | 18.8(1.3)% | |
fcc | - | 11.6(0.3)% | - | |
σ | 2.1(0.1)% | - | 3.9(0.3)% | |
Cr2B | 1.6(0.3)% | - | 2.2(0.2)% |
Background (in 600 s) | |||
---|---|---|---|
Sample (Boron Content) | At RT before the In-Situ Thermal Cycle | At HT | At RT after the In-Situ Thermal Cycle |
150 ppm B | 2450 | 2740 | 2440 |
500 ppm B | 2370 | 2530 | 2240 |
1000 ppm B | 2150 | 2460 before hcp-2 formation, 2110 after hcp-2 formation | 1900 |
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Beran, P.; Mukherji, D.; Strunz, P.; Gilles, R.; Karge, L.; Hofmann, M.; Hoelzel, M.; Rösler, J.; Farkas, G. Additional Phases at High Boron Content in High-Temperature Co–Re–Cr Alloys. Metals 2018, 8, 621. https://doi.org/10.3390/met8080621
Beran P, Mukherji D, Strunz P, Gilles R, Karge L, Hofmann M, Hoelzel M, Rösler J, Farkas G. Additional Phases at High Boron Content in High-Temperature Co–Re–Cr Alloys. Metals. 2018; 8(8):621. https://doi.org/10.3390/met8080621
Chicago/Turabian StyleBeran, Přemysl, Debashis Mukherji, Pavel Strunz, Ralph Gilles, Lukas Karge, Michael Hofmann, Markus Hoelzel, Joachim Rösler, and Gergely Farkas. 2018. "Additional Phases at High Boron Content in High-Temperature Co–Re–Cr Alloys" Metals 8, no. 8: 621. https://doi.org/10.3390/met8080621