Strengthening, loss of strength and embrittlement of beryllium under high temperature neutron irradiation

The 'dose' dependence of short-term mechanical properties of beryllium DIP- 600 with 2.3 wt% of oxygen was determined. Irradiation temperature was 650 degrees C, post-irradiation test temperature was 20 degrees C. The influenc e of the main structural factors on ultimate strength of warm- and hot-pres sed materials, characterized by oxygen content 0.7-4.9 wt%, grain size 8-50 mu-m, initial porosity 0.81-2.26% was revealed. The materials were irradia ted to a fast fluence of 4.67 x 10(21) n/cm(2) (E greater-than-or-equal to 0.85 MeV) at 620 degrees-C and that of 5.69 x 10(21) n/cm(2) (E greater-tha n-or-equal to 0.85 MeV) at 680 degrees-C. (C) 1999 Elsevier Science B.V. Al l rights reserved.