抄録
During drilling process for micro holes with high aspect ratio, the machining speeddecreases obviously after a certain depth, because of generation and evacuation of bubbles and debris in the narrow discharge gap area. In order to explore the relationship between the drilling depth and machining speed, a high speed camera was used to observe the behavior of bubbles and debris in the discharge gap area. Behaviors under different conditions were compared and the reason for the difference was discussed.