Oxidation property and homogenization treatment of plasma sintered beryllides

To evaluate the stability of the plasma-sintered beryllides at high temperature, the oxidation properties at 1273 K was studied using samples that had been treated with different sintering times at different phase distributions. With increased sintering times at 1273 K in the plasma-sintering process, the oxidation resistance increased. However, at high temperatures, degradations in the mechanical properties and chemical stability were found, which are associated with the existence of a Be2Ti phase. Consequently, we investigated the effect of annealing treatments on the phase stability of samples at 1273 K, 1473 K and 1673 K for homogenization. With treatment at 1273 K for 1 hr, no variation of phase occurred. As the temperature was increased to 1473 K, however, the Be2Ti phase as well as the Be phase were eliminated, while other phases showed no change. An annealing treatment at 1673 K for 1 hr resulted in a homogenized, pure Be12Ti phase. Armed with these results, by controlling not only the plasma-sintering time during the synthesis process but also the annealing time after synthesis of beryllide was complete, we were able to homogenize a Be12Ti phase, which is the compositional target. In light of the mechanical and chemical properties, our results should allow for optimization of the conditions for the granulation of beryllide.