Molecular dynamics investigation of rotation-assisted grinding process for GaN with layered heterostructure of the Wurtzite/Zinc-blende

Gallium nitride (GaN) with layered heterostructure of Wurtzite/Zinc-blende (WZ/ZB) has many excellent properties, but the thickness of the layered heterostructures and nano-grinding methods immensely affect the performance of the material. This study employs molecular dynamics (MD) simulation to examine the impact of rotation-assisted grinding on GaN with a layered heterostructure of WZ/ZB. The current research further focuses on the impact of grinding abrasive rotation period and WZ/ZB thickness on the microstructure of GaN after nano-grinding. This research involved the number of atoms removed, processing force, temperature, subsurface damage, radial distribution function (RDF), and dislocation analysis. Results have shown that rotation-assisted nano-grinding is highly effective in reducing both the machining force and the thickness of the subsurface damage layer. Additionally, it significantly reduces the degree of phase transition in the crystals. Being different from the single crystal, the existence of the heterostructure not only achieves a greater efficiency of surface removal but also reduces damage to the subsurface. Meanwhile, we observed that the layered heterostructure of the WZ/ZB had a great influence on the nucleation time of various dislocations and the length of other dislocations.