Tribochemical drilling of micro-hole on silicon nitride ceramics in ethanol

Abstract

There are growing industrial needs of micro-drilling of engineering ceramics. Among the ceramics, little study was conducted on micro-drilling on silicon nitride. In the present study, micro drilling on two kinds of silicon nitride with different kinds of additives (Si₃N₄ + Y₂O₃ and Si₃N₄ + Al₂O₃) were conducted in ethanol as the cutting fluid. The condition of the spindle rotational speed and the feed rate was clarified for safe drilling. The life of the diamond-coated drill is longer for Si₃N₄ + Y₂O₃ than for Si₃N₄ + Al₂O₃; referred to SiN-W, and SiN-B respectively. It is suggested that tribo-chemical reaction product; silicon alkoxide may effectively protect the damage of the drill point for SiN-W.