Effect of titanium content on mechanical properties and reactivity of titanium beryllide pebbles

Abstract

A combinational process for the fabrication of beryllide pebbles, consisting of a plasma-sintering method and the rotating electrode method for fabrication of electrode rods and pebbles, respectively, is proposed. To investigate the effect of Ti content in titanium beryllide pebbles on the pebbles’ crush strength and oxidation resistance, beryllide pebbles with 3–10.5at.% Ti were fabricated. Scanning electron microscopy (SEM) observations demonstrated that the surfaces of Be – 3 and 5at.% Ti pebbles contained a Be phase, whereas the surfaces of Be – 7–10.5at.% Ti pebbles did not. Moreover, according to cross-sectional SEM images, the area fraction of the Be phase decreased with increasing Ti content in beryllide pebbles with 3–9at.% Ti, whereas the pebble with 10.5at.% Ti consisted primarily of the Be17Ti2 phase. With regard to the mechanical properties of the pebbles, their strength and elongation decreased with increasing Ti content because of the brittleness of the Be phase. The weight gain and the amount of H2 generated by the pebbles under reaction with 1% H2O/Ar decreased with increasing Ti content, whereas the stability of the pebbles was strongly dependent on the presence of the Be phase on their surface.