Effect of up-milling and down-milling on tool life of CVD/PVD coated inserts

In this study, the tool life for up milling which has been widely used on conventional milling machine tools and down milling which is being used recently on CNC machine tools has been investigated. It is known that down milling technique increases the tool life due to having less chip length and rigid cutting conditions. It is aimed that change in the tool life to be defined as reliable numerical values using a cutting tool and work piece pair. Stainless steel blocks and H490 ANKX 120508PNTR - IC 830 inserts produced by ISCAR were used and up-milling and down-milling operations were applied on a CNC machine tool, with various cutting speeds and feed rates. After applying a certain cutting distance, the insert was removed from tool holder and examined using optical and tool-makers-microscope. Design of experiment - DOE procedure was prepared and surface responses for tool life were obtained. Results showed that, 12.52 % increase on the tool life for down milling compare with the up milling, whereas 12.92 % increase for slot milling were observed. As well as slot milling and down milling has given almost same tool life, the longest tool life was achieved by slot milling.Keywords : Down-milling, up-milling, tool life, CVD/PVD, coated inserts, carbide tools.