Effect of ZrO2 on sintering characteristics of MgO and MgO-Al2O3 system powder compacts

Effect of ZrO2 on the sintering characteristics of MgO powder compacts was studied. Addition of ZrO2 enhanced the sinterability of the MgO powder compacts and decreased the sintering temperature by about 200 degrees C. When a MgO powder compact with 10 mass% ZrO2 was heated, densification started at 1000 degrees C, and its relative density reached about 98% at 1200 degrees C, Addition of ZrO2 to powder compacts with various ratios of MgO to Al2O3 also increased the sinterability. Particulary, the relative density in compositions containing excess MgO over the equimolar composition of MgO and Al2O3 increased. When a 40 mass% MgO-60 mass% Al2O3 powder compact was heated at 1500 degrees 0 for 2h, the addition of 1 mass% ZrO2 improved the relative density from about 83% of the initial composition to about 97%.