Mechanism of high efficiency self-rotating grinding with low surface and subsurface damage in different oriented single-crystal diamond

Abstract

Single-crystal diamond (SCD) machining faces significant challenges due to its extreme hardness and anisotropic cleavage behavior. Understanding different oriented SCD material removal behavior is crucial for achieving high-quality and efficient processing. This study presents an efficient self-rotating mechanical grinding method for processing (100), (110) and (111) SCD planes. By tailoring processing parameters to the crystallographic traits, material removal rate exceeding 54.86 μm/h are achieved for different crystal planes. Under the optimized parameters, the surface roughness (Sa) for the (100) plane is below 0.6 nm, with no subsurface damage observed. Through multiscale characterization (TEM/SEM/XPS/Raman) and molecular dynamics (MD) simulations, we reveal that subsurface damage across all planes originates from (111) cleavage, yet manifests differently: (100) planes cleavage along < 110 > directions, (110) planes cleavage along both < 110 > and orthogonal < 112 > /< 1–12 > directions, and (111) planes exhibit horizontal peeling combined with 60°-tilted cleavages. This study clarifies the deformation and damage mechanisms of diamond crystals during ultraprecision machining, which is crucial for achieving efficient and high-precision manufacturing of diamond components.