Effects of Machining Parameters on Cutting Force of Endmilling of Inconel 718 Using Wavy-Edge Bull-Nose Helical End-Mill under Minimum Quantity Lubrication

Abstract

This paper investigates effects of machining parameters: cutting speed (CS), feedrate (FR), and axial depth of cut (DC), on cutting force of endmilling of Inconel 718. A Wavy-edge bull-nose helical endmill (WEBNHE) was simulated cutting this material, at different levels of these parameters, then the maximum values of cutting force components (FxMax, FyMax, FzMax), as well as the resultant (FMax) were predicted using a mechanistic cutting force prediction model developed and cited from references [1-3]. The mechanistic model predicts the cutting force based on instantaneous cross-sectional area of the chip, and the local differential cutting-edge length, whereas minimum quantity lubrication (MQL) cooling strategy was incorporated into the mechanistic model via experimentally-identified cutting force and edge force coefficients which were identified and cited from the reference [4]. The simulated experimental runs in this research were designed based on Full-factorial principle, whereas MATLAB was used to simulate the mechanistic model and predict the cutting forces. The resultes showed that depth of cut contributed the most (by 78.94%) on the predicted resultant force (FMax), Followed by Feedrate, which contributed by 20.56%, and last was the cutting speed which contributed only by7.13%. Resultes also showned that, increasing feedrate and depth of cut resulted in increasing the three cutting force components and the resultant, Whereas increasing the cutting speed resulted in decreasing the FxMax and FyMax, but increasing the FzMax. Furthemore, by focusing on the axial force component (FzMax), it was observed that the effect of cutting speed was completelly reversed when the feedrate reached 41 mm/min and depth of cut reched 25 mm. At these conditions, cutting speed 93 produced more FzMax than 62. This can be justified by the wavy-cutting edge affecting cutting force direction