Compatibility between Be–Ti alloys and F82H steel

Beryllium (Be) metal is a reference material for a neutron multiplier in the fusion blanket design. However, Be metal may have problems such as high reactivity and large swelling at high temperature and high neutron dose in the DEMO fusion blanket. Beryllium alloys such as Be–Ti are promising candidates for advanced neutron multipliers from the viewpoints of high melting point, high beryllium content, low radio-activation, and good chemical stability. In this study, the compatibility between Be–Ti alloys that include αBe phase and the structural material F82H was investigated. The reaction product of Be2Fe was analyzed by X-ray diffraction on the surface of F82H after compatibility testing. The thickness of the reaction layer for the Be–5at.%Ti and Be–7at.%Ti specimens was almost the same. And the thickness for these alloys tested at 800 °C for 1000 h was less than 50 μm, which is much smaller than the previously obtained value, ∼200 μm, for Be under the same conditions.