Irradiation hardening behaviors of large-scale hot rolling potassium-doped tungsten alloy under synergistic irradiations of Fe11+ ion combined with deuterium and helium plasmas. (March 2022) - Ma, Xiaolei
Highlights: A large-scale KW plate with the weight of 25 kg was prepared for the first time. The synergistic irradiation of Fe 11+ ion, He and D plasmas were performed on PW and KW. K bubble was proved to restrain the movement of W interstitial atoms and the clustering of vacancies produced during irradiation. Compared with PW, the KW shows a better irradiation hardening resistance. The irradiation hardening behaviors as well as their relationship with K bubbles were discussed in detail. Abstract: In this study, a 25 kg potassium doped tungsten (KW) plate dispersed K bubbles was prepared by hot rolling firstly. In order to evaluate the mechanical properties of KW after irradiation, the synergistic irradiation of Fe 11+ ion, He and D plasmas were performed on KW and pure tungsten (PW). 3.5-MeV Fe 11+ ion irradiation was used to simulate displacement damage induced by neutrons. The total fluence and irradiation temperature were 5.31 × 10 14 m −2 for 0.5 displacements per atom (dpa) damage and 400 K, respectively. Positron annihilation Doppler broadening spectrometry (PA-DBS) technique was applied to measure the type of defect in both undamaged and damaged PW & KW samples. The total ion fluence helium (He) and deuterium (D) were kept constant at 1 × 10 25 He m −2 and 5 × 10 24 D m −2, separately. Subsequently, the hardness value of PW and KW received from CSM nanoindentation technique was analyzed and compared. The results show that the increase of vacancy-type defects in KW is restrained after irradiation compared with PW. For un-irradiated PW and KW samples, there are almost the same pop-in events, which indicate that PW and KW a similar plastic deformation at room temperature. The KW shows a better irradiation hardening resistance than PW under the same irradiation condition. Besides, the evolution of irradiation hardening as well as their relationship with K bubbles were discussed in detail.