Strength of Sintered Alumina at Low Temperature Due to Ball Mill Abrasion Powder Seeding

Sinterability of low-temperature calcined α-alumina powder and the bending strength of sintered bodies were investigated. The α-alumina powder was made from commercial aluminum hydroxide with seeding of abrasion powder worn in the wet ball milling. The low-temperature calcined α-alumina powder was very fine and achieved the density of more than 3.8Mg/m3 by hot pressing at 1200°C. The microstructure of the sample sintered at low temperature was composed of very fine equiaxial gains in spite of low purity. The bending strength of this sample was more than 800MPa.