Atomistic understanding of scratching-induced material attrition of wurtzite single-crystal AlN using nanoscale diamond abrasive

The scratching-induced material removal behavior and mechanism of single-crystal AlN using single diamond abrasive were studied at atomic level through molecular dynamics simulation and nanowear test. A minimum removal thickness of monolayer is achieved on Al-terminated AlN(0001) surface in simulation. Dislocations and stacking fault constitute the main subsurface lattice damage and demonstrate positive correlations with the scratching depth. Both simulated and experimental results suggest that the plasticity-dominated nanowear of AlN can be properly described with the Archard-type model that relates the wear volume linearly to the normal load in a limited load range, but cannot be maintained at high load. This work provides atomic-level insights into mechanical material attrition of AlN and contributes basic knowledge to ultraprecision surface machining.