Machinability and contact damage of Al₂O₃/BN composites fabricated through chemical processing

The machinability and contact damage of Al₂O₃/BN nanocomposites fabricated through the chemical method were investigated in the present work. The Al₂O₃/BN microcomposites indicated considerably low fracture strength by adding BN particles, although machinability was improved. However, the nanocomposites showed both high fracture strength and good machinability. Hertzian contact test were performed to evaluate the contact damage. From the result of SEM observation of the samples after this test, it was found that the damage of the monolithic Al₂O₃ and Al₂O₃/BN microcomposites have a classical Hertzian cone fracture and many large cracks, respectively, whereas the damage observed in the nanocomposites appeared to be quasi-plastic deformation.