Investigation of AlN ceramic anisotropic deformation behavior during scratching

To explore the anisotropic deformation behavior of aluminum nitride ceramic during processing, ramp and constant load scratch experiments were conducted with Vickers indenter. Characteristics of deformation anisotropy were observed in ramp-load scratch with differences found in the directions of pile-ups, slip lines and cracks produced by grains with various orientations. Constant-load scratches were conducted to explore the anisotropic deformation behavior in plastic stage. Obvious differences were found in scratch pile-up height and residual depth of grains with different orientations. As the grain orientation Euler angle changes from the basal to the two prism surfaces, the residual depth of the scratch gradually increases. Molecular dynamics simulation was performed to disclose the mechanisms of anisotropic dislocation and deformation during scratching. The activation of the slip system for different grain orientations was calculated by a scratch Schmid factor model which was verified by the observation of pile-ups and slip lines around the scratches.

Automated summary

This study investigates the anisotropic deformation behavior of aluminum nitride ceramic during processing through ramp and constant load scratch experiments. It was found that the deformation anisotropy was characterized by differences in pile-ups, slip lines, and cracks produced by grains with different orientations. The mechanisms of anisotropic dislocation and deformation during scratching were disclosed through molecular dynamics simulation.