Numerical simulation of chipping formation process with smooth particle hydrodynamic (SPH) method for diamond drilling AIN ceramics

摘要

This paper presented a fundamental investigation on the edge chipping formation mechanisms involved in diamond drilling of AIN ceramics process with the smooth particle hydrodynamic (SPH) simulation method. The stress distribution of the material together with the nucleation/propagation process of the lateral cracking was investigated with the 3D/2D simulation models to explore the mechanistic origins behind the observed chipping features. Giving consideration to the machined cylinder morphologies, the mechanisms of chipping formation were explored with the contact mechanics theory of brittle material. Additionally, the formal drilling experiments were performed under different machining parameters, and the chipping widths were measured. It was detected that the incipient crack was nucleated at the contact edge of the machined surface, and its propagation in the circumferential direction resulted in the formation of the machined cylinder. Furthermore, the maximum effective stress presented itself beneath the contact corner along its normal direction, and the maximum shear stress was responsible for the chipping formation. Finally, the chipping widths of the numerical analysis were in accordance with the experimental measurements, revealing the feasibility of the SPH numerical model to simulate the edge chipping formation process.