-Ti合金のイオン照射した硬化挙動と微細組織の解析

Analysis of irradiation hardening behavior and microstructure of ion-irradiated -Ti alloys

若井 栄一  ; 叶野 翔*; 石田 卓*; 牧村 俊助*; 柴山 環樹*; 涌井 隆  

Wakai, Eiichi; Kano, Sho*; Ishida, Taku*; Makimura, Shunsuke*; Shibayama, Tamaki*; Wakui, Takashi

本研究では、照射環境下で使用される機器類の耐久性能の向上を目指し、Ti合金の内、-Ti合金の1つであるTi-15V-3Al-3V-3Sn(Ti-15-3を略す)のイオン照射による照射挙動と微細組織の変化を調べた。Ti-15-3合金の照射損傷分布は入射表面から深さ依存性を持つが、今回の観察から約9dpaの領域まで転位ループが観察されていないことが分かった。また、照射によるオメガ相形成を調べるため、回折パターン解析をしたところ、オメガ相の前駆体と思われるナノサイズの物質の形成による原子配列の乱れが観察されると共に、dpa増加に伴い、散漫散乱によるストリークが強くなった。一方、ナノインデンターによる硬さ測定では、同条件のTi-64材では、約1GPaの照射硬化が現れるのに対して、T-15-3材では、照射硬化がほとんど見られず、高い耐照射性を持つことが分かった。

In this study, the irradiation behavior and microstructural changes of Ti-15V-3Al-3V-3Sn (abbreviated as Ti-15-3), one of the beta-Ti alloys among the Ti alloys, were investigated by ion irradiation in order to improve the durability performance of equipment used in irradiation environments. depth dependence, but from the present observation, it was found that dislocation loops were not observed up to a region of about 9 dpa. In addition, diffraction pattern analysis was performed to investigate the formation of omega-phase by irradiation, and it was found that the atomic arrangement was disordered due to the formation of nano-sized materials that may be precursors of omega-phase, and that the diffuse scattering streaks became stronger with increasing dpa. On the other hand, irradiation hardening of about 1 GPa was observed in the Ti-64 material under the same conditions, while almost no irradiation hardening was observed in the T-15-3 material, indicating that it has high irradiation resistance.