Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model
The hydrogen diffusion process in ferritic steel during thermal desorption tests was simulated using the finite element method based on the two-dimensional diffusion-trapping coupled model. This model was first verified by experimental data to obtain a physically meaningful combination of trap/latti...
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doaj-93bf8e0592e14257a0fc24fc5caaca5e2021-03-13T00:03:45ZengMDPI AGMaterials1996-19442021-03-01141374137410.3390/ma14061374Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled ModelYafei Wang0Songyan Hu1Guangxu Cheng2School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, ChinaSchool of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, ChinaSchool of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, ChinaThe hydrogen diffusion process in ferritic steel during thermal desorption tests was simulated using the finite element method based on the two-dimensional diffusion-trapping coupled model. This model was first verified by experimental data to obtain a physically meaningful combination of trap/lattice parameters. Then, the effect of specimen geometry was studied by varying the height of cylindrical specimens with other parameters fixed at constant values. Simulation of desorption spectra with different specimen geometries indicates that the measurement of hydrogen concentration is not affected by the change in specimen geometry due to the mass conservation law, for original thermal desorption spectra (TDS), which are, however, unlikely to be detected in traditional experiments due to the necessity of specimen transfer procedures. Considering the hydrogen escape during rest time (specimen preparation/transfer/evacuation), the measured TDS curves are expected to be strongly dependent on the specimen geometry. The effect of specimen geometry on desorption spectra is more pronounced for smaller specimens, resulting in the dramatic decrease in peak flux and the increased error of Kissinger method in the determination of trap deactivation energy. The present study may contribute to better understanding and more reliable interpretation of the TDS curves by considering the size effect.https://www.mdpi.com/1996-1944/14/6/1374thermal desorption spectroscopyhydrogendiffusiontrappingsimulation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Yafei Wang Songyan Hu Guangxu Cheng |
spellingShingle |
Yafei Wang Songyan Hu Guangxu Cheng Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model Materials thermal desorption spectroscopy hydrogen diffusion trapping simulation |
author_facet |
Yafei Wang Songyan Hu Guangxu Cheng |
author_sort |
Yafei Wang |
title |
Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model |
title_short |
Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model |
title_full |
Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model |
title_fullStr |
Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model |
title_full_unstemmed |
Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model |
title_sort |
effect of specimen geometry on the thermal desorption spectroscopy evaluated by two-dimensional diffusion-trapping coupled model |
publisher |
MDPI AG |
series |
Materials |
issn |
1996-1944 |
publishDate |
2021-03-01 |
description |
The hydrogen diffusion process in ferritic steel during thermal desorption tests was simulated using the finite element method based on the two-dimensional diffusion-trapping coupled model. This model was first verified by experimental data to obtain a physically meaningful combination of trap/lattice parameters. Then, the effect of specimen geometry was studied by varying the height of cylindrical specimens with other parameters fixed at constant values. Simulation of desorption spectra with different specimen geometries indicates that the measurement of hydrogen concentration is not affected by the change in specimen geometry due to the mass conservation law, for original thermal desorption spectra (TDS), which are, however, unlikely to be detected in traditional experiments due to the necessity of specimen transfer procedures. Considering the hydrogen escape during rest time (specimen preparation/transfer/evacuation), the measured TDS curves are expected to be strongly dependent on the specimen geometry. The effect of specimen geometry on desorption spectra is more pronounced for smaller specimens, resulting in the dramatic decrease in peak flux and the increased error of Kissinger method in the determination of trap deactivation energy. The present study may contribute to better understanding and more reliable interpretation of the TDS curves by considering the size effect. |
topic |
thermal desorption spectroscopy hydrogen diffusion trapping simulation |
url |
https://www.mdpi.com/1996-1944/14/6/1374 |
work_keys_str_mv |
AT yafeiwang effectofspecimengeometryonthethermaldesorptionspectroscopyevaluatedbytwodimensionaldiffusiontrappingcoupledmodel AT songyanhu effectofspecimengeometryonthethermaldesorptionspectroscopyevaluatedbytwodimensionaldiffusiontrappingcoupledmodel AT guangxucheng effectofspecimengeometryonthethermaldesorptionspectroscopyevaluatedbytwodimensionaldiffusiontrappingcoupledmodel |
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1724222454822338560 |