We attempt to understand the mechanism of grain boundary embrittlement and hydrogen embrittlement of metallic materials and the degradation mechanism of nuclear materials. We also try to promote the development of high strength and high ductility metallic materials. For these purposes, we conduct first-principles calculations on the interaction between solute elements and lattice defects in metallic materials, etc.

(1) Interactions between defect structures and solute elements in Mg alloys
(2) Hydrogen trapping of defect structure in Al alloy
(3) Intergranular embrittlement and hydrogen embrittlement of steels
(4) Hydrogen trapping of defect structure in Zr alloy

M. Yamaguchi: “First-principles study on the grain boundary embrittlement of metals by solute segregation: Part I. iron (Fe)-solute (B, C, P, and S) systems”, Metallurgical and Materials Transactions A 42(2011)319-329. M. Itakura, M. Yamaguchi, D. Egusa, E. Abe: “Density functional theory study of solute cluster growth processes in Mg-Y-Zn LPSO alloys”, Acta Materialia 203(2021)116491. T. Tsuru, K. Shimizu, M. Yamaguchi, M. Itakura, K. Ebihara, A. Bendo, K. Matsuda, and H. Toda: “Hydrogen-accelerated spontaneous microcracking in high-strength aluminium alloys”, Scientific Reports 10(2020)1-8.