A Study on Surface Fracture of Alumina Ceramics

Abstract

A detailed study on surface fracture of alumina specimen was carried out with respect to the grain size under different stress conditions. Surface stresses were introduced on alumina specimens of different grain size by different testing methods such as (i) sliding scratch test (severe tensile stress), (ii) block - on- ring test (mild tensile stress) and (iii) nano-indentation test (severe compressive stress) and their behavior was studied in detail. The influence of grain size on the fracture behavior was noticed in the circumstance of severe tensile stress and the surface stress was estimated by FEM analysis. The mild tensile stress on alumina samples revealed very low wear rate and the wear behavior is independent on the grain size of alumina. Also, under severe compressive stress, the area of deformation was found to be independent on the grain size of alumina ceramics.