Gas effects on void formation in 14 MeV nickel ion irradiated pure nickel
1986; Elsevier BV; Volume: 141-143; Linguagem: Inglês
10.1016/0022-3115(86)90078-4
ISSN1873-4820
AutoresL.M. Wang, R.A. Dodd, G.L. Kulcinski,
Tópico(s)Fusion materials and technologies
ResumoNickel samples with various helium and oxygen concentrations have been irradiated with 14 MeV Ni ions at 500 °C to a fluence of 8 × 1019 ions/m2 (2 dpa at a 1-μm depth). Helium atoms with energy varying from 200 to 700 keV were pre-injected at room temperature. The samples with low oxygen content were obtained by a hydrogen reduction treatment and high vacuum outgassing. The density and the average diameter of voids were determined by TEM examination of cross-section specimens. In the as-received Ni which was cold-worked, a heterogeneous void distribution was observed that could be attributed to the heterogeneous oxygen distribution. In the specimen irradiated after vacuum annealing at 800°C for one hour, voids are uniformly distributed. Small amounts of helium (10 appm) enhanced the void nucleation remarkably in both high (180 appm) and low (75 appm) oxygen content samples, while larger amounts of helium (30 appm) reduced the observable void density in the high oxygen content sample. The void density is much lower and the void size is much larger in the low oxygen content samples compared to those observed in the high oxygen content samples.
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