Analysis of thermal desorption of hydrogen in metallic alloys

Fleck, NA; Deshpande, VS; Raina, A

Analysis of thermal desorption of hydrogen in metallic alloys

cam.issuedOnline	2017-11-20
dc.contributor.author	Fleck, NA
dc.contributor.author	Deshpande, VS
dc.contributor.author	Raina, A
dc.contributor.orcid	Fleck, Norman [0000-0003-0224-1804]
dc.date.accessioned	2020-01-20T15:25:57Z
dc.date.available	2020-01-20T15:25:57Z
dc.description.abstract	The degree of embrittlement of metallic alloys is sensitive to the concentration of absorbed hydrogen, with hydrogen traps (particularly at grain boundaries) playing an important role. Thermal desorption spectrometry (TDS) is widely used to measure the detrapping and diffusion behaviour of hydrogen in metallic alloys. However, it is problematic to obtain a consistent interpretation of TDS data from the literature, due to the large number of material parameters that influence the measurement, and this results in a wide range of quoted values for trapping parameters such as the number of trap types, trap binding energies and trap densities. In this paper, the governing partial differential equation for hydrogen diffusion with sink and source terms for a single trap is formulated in non-dimensional form, assuming local equilibrium between the hydrogen atoms at the lattice sites and the trap sites. An asymptotic analysis reveals two distinct regimes of diffusion behaviour in TDS tests. Kissinger-type behaviour is expected in a TDS test for low heating rates on an alloy with a low lattice activation energy. Contour maps of maximum hydrogen flux and the corresponding temperature are plotted using axes of trap density and trap binding energy by making use of the full numerical solution (and asymptotic solutions). These maps serve as a useful tool for an accurate and simple determination of the trap binding energy as well as the trap density.
dc.description.sponsorship	ERC H2020 GA669764
dc.identifier.doi	10.17863/CAM.48116
dc.identifier.issn	1359-6454
dc.identifier.uri	https://www.repository.cam.ac.uk/handle/1810/301039
dc.language.iso	eng
dc.publisher	Elsevier
dc.rights	Attribution-NonCommercial-NoDerivatives 4.0 International
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.title	Analysis of thermal desorption of hydrogen in metallic alloys
dc.type	Article
dcterms.dateAccepted	2017-11-05
prism.publicationName	Acta Materialia
pubs.funder-project-id	European Commission Horizon 2020 (H2020) ERC (206409)
rioxxterms.licenseref.startdate	2017-11-05
rioxxterms.licenseref.uri	http://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.type	Journal Article/Review
rioxxterms.version	AM
rioxxterms.versionofrecord	10.1016/j.actamat.2017.11.011