R-SUS304ULC/Ta/Zr拡散接合界面の組織解析

Zrとステンレス鋼の異材接合に関する研究(第1報)

抄録

Microstructural analyses of the bonding interface in R-SUS304ULC/Ta/Zr diffusion bonded joints were conducted in order to clarify the embrittlement behavior of the joint. Diffusion bonding of R-SUS304LUC/Ta/Zr was carried out at 1073-1473 K for 0-10 ks in vacuum. SEM and TEM observations revealed that the production layer was formed at the R-SUS304ULC/Ta interface, and that the transition zone existed at the Ta/Zr interface. The intermetallic compounds such as TaFe₂, (Fe, Ni)₂Ta and TaCr₂ were identified in the production layer, however, only Ta was precipitated on α-Zr matrix in the transition zone. The Burgers' orientation relation was almost held between Ta and α-Zr. The hardened area was located at the R-SUS304ULC/Ta and Ta/Zr interfaces, and the severe embrittlement was occurred at the bonding interfaces when the bonding temperature was increased. The growth of the production layer could be expressed by the parabolic growth law, while the growth kinetics of transition zone was complicated during bonding operation.