Abstract
Machinable ceramics can be shaped by cutting, drilling and tapping with commercial tools. The purpose of this paper is to study the influence of tool geometry on machined surface and chipping size in ceramics drilling. The cutting performance of machinable ceramics is investigated and discussed from the viewpoint of the relation among tool wear, roughness of the machined surface and chipping size on the exit side in the hole. The experiment of drilling machinable ceramics were carried out with twist drill of high speed steel by drilling machine.
The main results obtained were as follows: (1) The chipping in the hole exit side decreased in low cutting speed and low feed in the drilling. (2) The chipping decreases at 75° (MMC material) drill point angle or 90° (Si3N4-BN MC material). (3) Si3N4-BN MC was smaller than MMC for abrasion and steady abrasion and abrasion initial stage drilling. (4) The progress of the tool wear increases the chipping in the hole exit side.
