Sintering Characteristics of Binary Alumina Powder Mixtures

Abstract

Sinterability of bimodal Al₂O₃ powders with average sizes of 3.9μm (c particle) and 0.6μm (f particle) and bending strength of their sintered bodies were investigated. Sintering between f and c particles progressed gradually at 1500°C with time. Densification behavior of mixed powders between 1400° and 1600°C could be classified into three mixing ratio groups. The observed differences in densification were considered to be caused by the different arrangement of f and c particles in the compacts from the SEM observation. Bending strengths of the samples sintered at 1600°C for 2h showed almost constant values around 30kgf/mm² for mixing ratios c:f between 1:9 and 5:5, but dropped rapidly at the ratios more than 5:5.