Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications
The directional spectral emissivity of a Ti–48Al–2Nb–2Cr alloy (in at.%), 4822 alloy, and a Ti-43.5Al–4Nb–1Mo-0.1B alloy (in at.%),TNM alloy, used in the aeronautical industry, are measured between 150 and 850 °C. The differences in the emissivity values between both alloys at the lowest temperature...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-11-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785423026133 |
| _version_ | 1797301532447735808 |
|---|---|
| author | L. Usategui I. López-Ferreño T. Echániz M. Sainz-Menchón M. Musi H. Clemens G.A. López |
| author_facet | L. Usategui I. López-Ferreño T. Echániz M. Sainz-Menchón M. Musi H. Clemens G.A. López |
| author_sort | L. Usategui |
| collection | DOAJ |
| description | The directional spectral emissivity of a Ti–48Al–2Nb–2Cr alloy (in at.%), 4822 alloy, and a Ti-43.5Al–4Nb–1Mo-0.1B alloy (in at.%),TNM alloy, used in the aeronautical industry, are measured between 150 and 850 °C. The differences in the emissivity values between both alloys at the lowest temperatures, indicates that the βo phase, only present in TNM, exhibit higher emissivity values. By numerical integration of the measured data, the total directional and hemispherical emissivity have been calculated. At 850 °C the total hemispherical emissivity in vacuum are nearly identical with 0.274 ± 0.006 for the 4822 alloy and 0.273 ± 0.007 for the TNM alloy. The lower emissivity change with temperature measured in TNM alloys is related with the deconvolution of βo phase by diffusion processes. Afterwards, near-normal spectral emissivity measurements are performed in both alloys during isothermal oxidation treatments at 750 °C and 850 °C for 120 h. The emissivity data reveal that the TNM alloy exhibits higher oxidation resistance especially at 750 °C. In parallel, microstructural characterization has been performed before the measurements, after the directional emissivity measurements prior to oxidation and after isothermal oxidations. The formed oxide scale is composed of four layers that coincide with those reported in the literature: an outer layer of TiO2 contiguous with a layer of Al2O3, followed by a TiO2/Al2O3 mixed layer and finally a thin layer of Nb-rich nitride. This mixed layer governs the interferential part of the alloys’ emissivity spectra, which, in combination with the background, determines the overall radiative behavior of the alloys under service conditions. |
| first_indexed | 2024-03-07T23:23:55Z |
| format | Article |
| id | doaj.art-862fc575aebc4047a4e3bb88d627506e |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-07T23:23:55Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-862fc575aebc4047a4e3bb88d627506e2024-02-21T05:26:35ZengElsevierJournal of Materials Research and Technology2238-78542023-11-012731703179Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applicationsL. Usategui0I. López-Ferreño1T. Echániz2M. Sainz-Menchón3M. Musi4H. Clemens5G.A. López6Applied Mathematics, University of the Basque Country (UPV/EHU), E-01006 Vitoria-Gasteiz, SpainApplied Mathematics, University of the Basque Country (UPV/EHU), E-01006 Vitoria-Gasteiz, Spain; Corresponding author.Applied Mathematics, University of the Basque Country (UPV/EHU), E-48013 Bilbao, SpainPhysics Department, University of the Basque Country (UPV/EHU), E-48940 Leioa, SpainDepartment of Materials Science, Montanuniversität Leoben, Franz Josef-Str. 18, 8700 Leoben, AustriaDepartment of Materials Science, Montanuniversität Leoben, Franz Josef-Str. 18, 8700 Leoben, AustriaPhysics Department, University of the Basque Country (UPV/EHU), E-48940 Leioa, SpainThe directional spectral emissivity of a Ti–48Al–2Nb–2Cr alloy (in at.%), 4822 alloy, and a Ti-43.5Al–4Nb–1Mo-0.1B alloy (in at.%),TNM alloy, used in the aeronautical industry, are measured between 150 and 850 °C. The differences in the emissivity values between both alloys at the lowest temperatures, indicates that the βo phase, only present in TNM, exhibit higher emissivity values. By numerical integration of the measured data, the total directional and hemispherical emissivity have been calculated. At 850 °C the total hemispherical emissivity in vacuum are nearly identical with 0.274 ± 0.006 for the 4822 alloy and 0.273 ± 0.007 for the TNM alloy. The lower emissivity change with temperature measured in TNM alloys is related with the deconvolution of βo phase by diffusion processes. Afterwards, near-normal spectral emissivity measurements are performed in both alloys during isothermal oxidation treatments at 750 °C and 850 °C for 120 h. The emissivity data reveal that the TNM alloy exhibits higher oxidation resistance especially at 750 °C. In parallel, microstructural characterization has been performed before the measurements, after the directional emissivity measurements prior to oxidation and after isothermal oxidations. The formed oxide scale is composed of four layers that coincide with those reported in the literature: an outer layer of TiO2 contiguous with a layer of Al2O3, followed by a TiO2/Al2O3 mixed layer and finally a thin layer of Nb-rich nitride. This mixed layer governs the interferential part of the alloys’ emissivity spectra, which, in combination with the background, determines the overall radiative behavior of the alloys under service conditions.http://www.sciencedirect.com/science/article/pii/S2238785423026133A. IntermetallicsB. Surface propertiesThermal properties and oxidationD. MicrostructureF. Spectroscopic methodsVarious and electron microscopy |
| spellingShingle | L. Usategui I. López-Ferreño T. Echániz M. Sainz-Menchón M. Musi H. Clemens G.A. López Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications Journal of Materials Research and Technology A. Intermetallics B. Surface properties Thermal properties and oxidation D. Microstructure F. Spectroscopic methods Various and electron microscopy |
| title | Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications |
| title_full | Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications |
| title_fullStr | Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications |
| title_full_unstemmed | Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications |
| title_short | Emissivity measurements conducted on intermetallic γ-TiAl-based alloys for aeronautical applications |
| title_sort | emissivity measurements conducted on intermetallic γ tial based alloys for aeronautical applications |
| topic | A. Intermetallics B. Surface properties Thermal properties and oxidation D. Microstructure F. Spectroscopic methods Various and electron microscopy |
| url | http://www.sciencedirect.com/science/article/pii/S2238785423026133 |
| work_keys_str_mv | AT lusategui emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications AT ilopezferreno emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications AT techaniz emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications AT msainzmenchon emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications AT mmusi emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications AT hclemens emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications AT galopez emissivitymeasurementsconductedonintermetallicgtialbasedalloysforaeronauticalapplications |