AIST and Kyushu University co-established AIST-Kyushu University Hydrogen Materials Laboratory “HydroMate” on 11th January 2017. This is based on basic policy of translation of government-affiliated organization by “Machi- Hito-Shigoto Sosei Honbu”.
   AIST’ strategy is to make a fusion of mechanical engineering and materials science for fundamental studies on complicated phenomena of hydrogen embrittlement of metals. AIST has materials scientists and engineers with unique techniques to observe behaviors of crystalline structures of nanometer scale. HYDROGENIUS in Kyushu University has a world reputation on their mechanical engineering approaches to the strength of metals in high pressure hydrogen gas. By the collaboration of the two groups, HydroMate will explore new approaches to understand hydrogen embrittlement and make a breakthrough to develop new, reliable and economical materials to be used in hydrogen energy systems. HydroMate also makes effort to make a network with industries, academia and governmental organizations and act as a “bridge” to industries for future development of innovative materials.

Research Topics

Microscale analysis of hydrogen effect on various strengthening mechanisms Study of fundamental mechanisms of HE on precipitation-strengthened materials via multiscale analysis.
Macroscopic tensile properties of materials are determined by mutually combining various strengthening mechanisms such as solid solution, dislocation, precipitation, and boundary strengthening mechanisms. Thus, the precise interpretation of their macroscopic tensile properties needs to understand the effect of hydrogen on each strengthening mechanism. In this project, we separately evaluate the effect of hydrogen on deformation behaviors at various scales by using nano- indenter and micro-hardness tester and clarify the effect of hydrogen on each strengthening mechanism. Whereas the precipitation-strengthening treatment drastically increases material strengths, this treatment sometimes enhances hydrogen sensitivity of materials. For developing new high-strength metals with excellent resistance to HE, this project investigates the effect of tensile and fatigue crack growth properties of various precipitation-strengthened metal. In addition, we performs detailed observations of crack growth behavior by means of SEM/EBSD, finally elucidating the HE mechanism of the precipitation-strengthened materials via multiscale analysis.
Nano-meso-macro analysis of hydrogen uptake in aluminum alloy Hydrogen diffusion-elastoplastic coupling analysis by finite element method
As the fundamental research on hydrogen uptake in aluminum alloy, hydrogen state in the aluminum alloy is investigated by using secondary ion mass spectroscopy (SIMS) and thermal desorption analysis (TDA). We investigate the hydrogen state in the aluminum alloy from measurement of bulk hydrogen content and calculation of trapping energy by TDA and local hydrogen content by SIMS. Quantitative understanding of distribution of hydrogen concentration around crack tip is considered to be needed for capturing the phenomenon of fatigue crack growth acceleration in presence of hydrogen. However, the hydrogen-diffusion properties of materials are dependent on plastic strain and hydrostatic stress; thus, the prediction of its distribution is very complicated. This project quantitatively evaluate the distribution of hydrogen concentration based on hydrogen diffusion-elastoplastic coupling analysis by FEM and aims to elucidate factors dominating the acceleration of fatigue crack growth in presence of hydrogen.