Effects of helium on the mechanical properties and microstructure of niobium |
| |
Authors: | W L Barmore E L Raymond C J Echer R R Vandervoort |
| |
Affiliation: | (1) Metals and Ceramics Division, Lawrence Livermore Laboratory, 94550 Livermore, CA;(2) Materials Test and Evaluation, Section of Materials Engineering Division, Lawrence Livermore Laboratory, 94550 Livermore, CA |
| |
Abstract: | Mechanical property specimens of niobium (Cb) were doped with helium by the tritium trick to concentrations as high as 500
appm. The tritium decays by the reaction3H →3He +β
− at a rate that produces about 7 appm per day in the host microstructure. Tensile properties were measured from room temperature
to 800°C, and creep properties from 700 to 1000°C at stresses from 45 to 75 MPa. Transmission electron microscopy was used
to study the microstructure of the helium doped specimens, and the observations were correlated with the mechanical property
results. The results of this investigation showed that niobium has a high tolerance to helium trapped in the microstructure.
The tensile and creep strengths of niobium increased as helium concentration increased. The ductility decreased significantly
as the helium concentration increased, but niobium retained substantial ductility even at a high helium concentration of 500
appm. This amount of helium would be generated by (n,α) reactions in the microstructure of a niobium first wall after a 20
y exposure in a D-T fusion reactor. Thus, niobium and niobium alloys are potential candidates for high temperature structural
materials in D-T fusion reactors. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|