Abstract
SPS consolidation of two ultrafine α-alumina powders (TM-alumina with 100nm and AA-alumina with 230nm) was examined under the two pressurizing conditions of 30MPa and 100MPa. It was found that densification behavior under 30MPa was influenced by the grain size of raw powder alumina and the influence of grain size on the densification was remarkably suppressed under 100MPa. It was also indicated that the grain growth was fairly suppressed in the consolidation of TM-alumina powder even when the powder was consolidated at a higher temperature than 1300°C. Further, the growth of crystallite was suppressed by increasing the applied pressure from 30MPa to 100MPa. Under the condition of 100MPa, nano-structural aluminas with less than 300nm and about 500nm were synthesized by consolidating TM-alumina at 1150°C and AA-alumina at 1200°C, respectively, indicating that SPS method has high capabilities of synthesizing nano-structured ceramics.
