Analysis of milling of iron aluminides

The machinability of an ordered iron aluminide compound, assessed by peak cutting force values, under milling conditions was studied. The machinability of the material focused over the following range of conditions: speed from 25 to 400 sfpm (7.5–120 m/min); feed from 0.001 to 0.003 ipt (0.025–0.075 mm per tooth) and 4–56 ipm (0.1–1.4 m/min); and depth of cut (DOC) from 0.005 to 0.030 in. (0.125–0.750 mm). The study was used to establish a general understanding of the machinability of the material. A cutting force model based on Yellowley’s constant cutting pressure model was developed. Comparison of simulated cutting forces and measured cutting forces under a variety of different cutting parameter settings were made to verify the cutting model. Tool wear as a function of speed and cutting force was also studied. The study concludes that high-speed tools cannot be used to machine iron aluminides. The cutting forces during milling of iron aluminides are 1.5–3.5 times of those measured during machining of medium carbon steels and on a scale of 100, the machinability rating of iron aluminides is about 13.7. In addition, in order to prevent failure or very large cutting forces, the maximum cutting speed and DOC that can be used to machine iron aluminide are found to be 200 sfpm (60 m/min) and 0.015 in. (0.375 mm), respectively.