When precipitation hardened Alloy 718 is irradiated with high-energy protons (600?800 MeV) and spallation neutrons at temperatures below 60C, it quickly hardens and loses almost all uniform elongation. It later softens somewhat at higher exposures but does not regain any elongation. This behavior is explained in terms of the evolution of Frank loop formation, disordering and eventual dissolution of the ?' and ?? strengthening phases, and the steady accumulation of very large levels of helium and hydrogen. These gases must be dispersed on a very fine scale in the matrix since no cavities could be found.
Revised: February 18, 2003 |
Published: December 1, 2000
Citation
Sencer B.H., G.M. Bond, F.A. Garner, M.L. Hamilton, B.M. Oliver, L. Thomas, and S.A. Maloy, et al. 2000.Microstructural evolution of Alloy 718 at high helium and hydrogen generation rates during irradiation with 600-800 MeV protons.Journal of Nuclear Materials 283, no. Part A:324-328.PNNL-SA-36926.