Abstract

Excellent and superior properties of alumina (Al2O3) nanocrytalline ceramic make it a one of the highly demanded advanced ceramics in the present competitive scenario of manufacturing and industrial applications. α-Αl2O3 nanoparticles with average particle size of 3.4, 5.2, 7.2 and 12.5 nm a series of Αl2O3 nanocrystalline ceramic samples were prepared by grain size variation. (Two-step sintering). The inverse Hall Pitch relationship between the microhardness and grain size of Αl2O3 nanocrystalline ceramic was observed. Critical grain size exists at which the properties of α- Αl2O3 nanocrystalline ceramics change significantly. Indentation method was employed to test the fracture toughness of Αl2O3 nanocrystalline ceramic.