Comparison between Up-milling and Down-milling Operations on Tool Wear in Milling Inconel 718

The demand for the use of nickel-based superalloy such as Inconel 718 is increasing in aerospace industry as it is efficient for energy and has excellent properties. In this paper, the experimental studies of tool wear mechanism and tool life in ball nose end milling of Inconel 718 is presented under minimum quantity lubricant (MQL) condition. The evaluations of the results are focusing on the comparison of up-milling and down-milling operations using physical vapor deposition (PVD) - coated carbide inserts. Machining parameters; depth of cut, feed rate and cutting speed are considered during the evaluation. The experimental results showed that down-milling operation has better results in terms of tool wear than up-milling operation. Chipping on cutting tool edge was the primary reason that responsible to notch wear with prolong machining.