LAUSR

Abstract Corundum abrasives with plate-like grains were fabricated by a two-step sintering technique using the solution-based process with the addition of the ternary compound additive Na 3 AlF 6 -CaO-SiO 2 . The two-step sintering method showed obvious advantages over conventional sintering methods in promoting sample densification, suppressing grain growth, and homogenizing the microstructure of the corundum abrasives. The sample doped with 2.5 wt% Na 3 AlF 6 and 4 wt% CaO + SiO 2 in the molar ratio of 1:1 possessed a relative density of 99.3%, average grain size of 0.54 µm, and single-particle compressive strength of 49 N. The introduction of seeds reduced the temperature of θ- to α-Al 2 O 3 phase transformation. The relationship between the microstructure and the mechanical properties of the abrasives was also discussed.