Preparation of rare earth oxide doped alumina ceramics, their hardness and fracture toughness determinations

Abstract

Alumina based ceramics doped with rare earth oxide (Y₂O₃) of 500 ppm, 1000 ppm and 2000 ppm were prepared by following ceramic powder processing and solid state sintering at 1500°C for different soaking time periods of 3 h, 6 h and 9 h. Microstructural investigations on all the samples were carried out. Hardness measurements were conducted using Vickers Indentation technique. Fracture toughness of the samples was estimated by inducing radial cracks by various indentation loads on the samples. The measured hardness values were found to lie between 139 MPa and 1444 MPa, while the fracture toughness values lie in the range 1.65-5.76 MPa m^1/2