Low-Temperature Hot Pressing of ZrB2-Based Ceramics with ZrSi2 Additives

Densification of zirconium diborides (ZrB2) was examined by hot pressing at different temperatures ranging from 1350 degrees C to 1500 degrees C with sintering additives of zirconium disilicide (ZrSi2), ranging from 10 vol% to 40 vol%. The effect of the amount of ZrSi2 additives on the densification of ZrB2 was assessed. The sinterability of ZrB2 with ZrSi2 additives was significantly improved, and this improvement was enhanced with the increasing ZrSi2 added. The relative density exceeding 94% was obtained for the studied ZrB2 ceramics with ZrSi2 additives at a temperature equal to or above 1450 degrees C, depending on the amount of additive. With 10 vol% ZrSi2 additions, the relative density increased from 79.3% at 1350 degrees C to 96.5% at 1500 degrees C. With additions equal to or above 20 vol% ZrSi2, a relative density exceeding 96% was obtained at 1450 degrees C, and the nearly fully dense ZrB2 compacts were obtained at 1500 degrees C.