Study on Micro Diameter Drill Working : Effects of Working Conditions on Burr and Cutting Force

This work was studied for the influence of working conditions ; drill point shapes, drill feed, cutting speed, workpiece structure on burr in plastic deformation and cutting force in micro drilling. The results are as follows ; Drilling with duller shaped drills causes to form remarkable burr. Burr weight in micro drilling, however, in spite of extremely dull condition of drill point shapes, has a tendency of decreasing in workpiece with larger crystal grains and minute cut depth. And cutting force in drilling of same feed becomes larger in the case of drilled part characterized with large number of crystal grains. As the reason of these phenomenon in micro drilling, the effects of crystal structure in workpiece and micro protrusions on lip are considered, because of the speciality for the minuteness of drilled shapes and units