Interpretation of thermal desorption spectra of hydrogen from aluminum using numerical simulation

Abstract

In the development of high strength aluminum alloys, hydrogen embrittlement is a crucial problem. In order to understand hydrogen embrittlement, it is inevitable to know hydrogen trapping states in the alloys and it can be identified using thermal desorption spectrometry of hydrogen. We numerically simulated thermal desorption spectra of hydrogen in aluminum which are reported for a cylindrical specimen and for a plate specimen, and interpreted the desorption peaks included in them on the basis of the trap site concentration and the trap energy. As a result, we found that the peak at the lowest-temperature side can result from grain boundaries, although it was confirmed that the reported interpretation for other peaks is reasonable. In addition, we obtained the result showing the possibility that the trap site concentration of dislocations and vacancies changes during the process of heating the specimens.