Influence of coolant conditions in ultrasonic assisted grinding of high performance ceramics

Ultrasonic-assisted grinding finds its main application in the processing of hard, brittle materials. In particular through the superposition of the conventional feed rate and the high velocity with ultrasonic frequency, advantages in drilling processes can be reached. The application of ceramic and glass materials for high performance parts in the aerospace and aeronautical industries, in biomedical components and for parts exposed to wear in the automotive industry is steadily increasing due to their favorable properties. The drilling of these materials in their sintered state with high accuracy and reproducibility presents a significant challenge with respect to the choice of tool and the process parameters implemented. This paper focuses on the influence of the cooling lubricant in combination with different tool specifications on the grinding process. The grain size of the diamond grinding pins was varied in the range of 30 to 126 μm. As bond types, electroplated, sintered bronze and sintered Fe/Co bonds were investigated as well as the pressure of the cooling lubricant and the influence of these factors on the process behavior. In additional to the process behavior, the residual stress profiles of the workpieces were evaluated.