Mechanisms in oxide-carbide ceramic BOK 60 grinding

The paper presents an experimental study of micro-cutting intended to aid the optimization of the grinding process of the oxide-carbide ceramic BOK 60. The necessity for investigating the mechanisms occurring between the abrasive material and the ceramic is imposed by the fact that grinding is the dominant technology used to achieve the required quality of the workpiece surface finish. The investigations were carried out to determine the normal and tangential cutting forces, the critical penetration depth, and the crack generation angle on the workpiece surface as a function of the grain penetration speed and depth. The micro-cutting process was performed with a single diamond cone-shaped grain at varying depths of cut. It was found that the critical grain penetration depth separating ductile flow from brittle fracturing ranges from 3 to 5 mu m, while radial cracks on the ceramic's surface are distributed at an angle from 35A degrees to 75A degrees, measured relative to the direction of the diamond grain's motion.