Study on Preparation of B₄C-Zircaloy Annular Burnable Absorber

B₄C-zircaloy annular burnable absorber pellet was prepared by powder metallurgy method,using Zr-2 hydride powder and B₄C powder as raw materials,compacted by rubber isostatic pressing method,dehydrogenated in vacuum furnace.It is sintered at 800~1100℃ about an hour.The theoretical density and open porosity were tested by immersion method.The effect of the B₄C content and sintering temperature on the sintering performance of the B₄C-Zircaloy were studied.The microstructure of green body and sintered body were analyzed by SEM.B₄C hinders the densification of sintered body,the relative density of the sintered body were increasing with the decreasing of B₄C content and increasing of sintering temperature.The particle of B₄C distribute uniformly.When the B₄C content was 0.5% and the sintering temperature above 1000℃,the relative density of the sintered body reaches 95%,and the open porosity is lower than 1%.