Two-step sintering behavior of sol–gel derived nanocrystalline corundum abrasive with MgO–CaO–SiO2 additions

摘要

Nanocrystalline corundum abrasive with mean crystal size of less than 100 nm was synthesised by sol–gel process via two-step sintering technique. A remarkable suppression of grain growth was achieved by controlling sintering temperature and taking advantage of sintering aids (MgO–CaO–SiO2) 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 seven times less than that of the samples made by the conventional sintering technique. The microstructure of the samples was homogeneous without abnormal grain growth and the obtained corundum abrasive exhibited excellent abradability compared to conventional sintering methods.