Novel surface characteristics observed during grinding of polycrystalline diamond

The use of diamond is ubiquitous in many engineering applications, yet its processing by conventional machining methods continues to pose challenges owing to its extreme hardness and chemical inertness. Grinding polycrystalline diamond workpieces is a viable commercial method used to obtain nanometric smooth and damage-free surfaces. In light of the novel experimentation work, this study shed light on the fundamental material challenges encountered during the nanoscale grinding of polycrystalline diamonds with resin-bonded diamond wheels. The experimental results revealed a strong influence of the grain orientation in affecting the paradigm of the material removal such that a particular orientation of diamond showed some “ripple” like surface structures that could not be smoothed even using the post-grinding plasma operation. The in-situ experimental analysis as well as the complementary molecular dynamics simulations involving the use of a long-range Screening bond order potential function offered new insights into the mechanism of “ripple formation” and C[dbnd]C bonds observed on the (110) oriented diamond surface. Furthermore, in-situ observation experiments revealed that the ripple-like structure followed periodic recurrence, suggesting that the material removal rate during the process of grinding is influenced periodically in a recurring manner.