Low-Temperature Hot Pressing of ZrB_2-Based Ceramics with ZrSi_2 Additives

摘要

Densification of zirconium diborides (ZrB_2) was examined by hot pressing at different temperatures ranging from 1350℃ to 1500℃ with sintering additives of zirconium disilicide (ZrSi_2), ranging from 10 vol% to 40 vol%. The effect of the amount of ZrSi_2 additives on the densification of ZrB_2 was assessed. The sinterability of ZrB_2 with ZrSi_2 additives was significantly improved, and this improvement was enhanced with the increasing ZrSi_2 added. The relative density exceeding 94% was obtained for the studied ZrB_2 ceramics with ZrSi_2 additives at a temperature equal to or above 1450℃, depending on the amount of additive. With 10vol% ZrSi_2 additions, the relative density increased from 79.3% at 1350℃ to 96.5% at 1500℃. With additions equal to or above 20 vol% ZrSi_2, a relative density exceeding 96% was obtained at 1450℃, and the nearly fully dense ZrB_2 compacts were obtained at 1500℃.