Evaluation of the Performance of Micro-Drills in Drilling a Machinable Ceramic Material

摘要

The performance of three different micro-drills in drilling a machinable ceramic material is evaluated in terms of the critical feed speed (mm/min) at a given rotation rate (rpm). The critical speed is the feed speed from and above which the chipping on the rear side of the machinable ceramic material takes place. The determined critical speed increases with the rotation rate in the tested range of 2k-8k rpm, forming the critical boundary line. The drilling performance of the micro-drills can be evaluated quantitatively using the position of the critical boundary lines in the space of feed speed vs. rotation rate: The higher the critical boundary line, the higher the drilling performance of the micro-drill.