Synthesis and two-step sintering behavior of sol–gel derived nanocrystalline corundum abrasives

Nanocrystalline corundum abrasive with mean crystal size of less than 100 nm was synthesized by two-step sintering method using sol–gel process. A remarkable suppression of grain growth was achieved by controlling sintering temperature and taking advantage of sintering aids during the final stage of a two-step sintering process. The grain size of the high densification samples (>99% theoretical density) produced by two-step sintering method was about 10 times less than the samples made by the conventional sintering technique. The microstructure of the samples was homogeneous without abnormal grain growth and the sol–gel derived corundum abrasive with two-step sintering technique exhibited excellent mechanical properties and wear resistance compared to those sol–gel derived corundum abrasive with conventional sintering methods and fused corundum abrasive.