Nanomechanical properties of coarse grain alumina ceramic

The hardness of alumina ceramics determines their performance in high end structural applications like wear resistant inserts, coatings, cutting tools, biomedical load bearing implants and armor face plate etc. Therefore, the nano-hardness (H) and Young’s modulus (E) of a pressureless sintered, 99.99% dense, 10 μm grain size alumina were measured by nanoindentation at 10 mN to 1000 mN load with a Berkovich indenter. The decrease in nano-hardness with the increase in indentation depth revealed the presence of an indentation size effect (ISE) which was explained by the application of the well established Nix and Gao model. The measured value of Young’s modulus (400 GPa) was insensitive to variation in loads applied during the nanoindentation experiments