Analysis of the machinability of the alloyed iron aluminide Fe-Al-Si-Nb by WEDM

Wire electrical discharge machining is an unconventional machining technology used in many industries. The machinability analysis of the newly-created materials is crucial for their future machinability with the given machining technology. For the machinability analysis, the influence of the machining parameters, namely pulse off time, gap voltage, discharge current, pulse on time and wire feed, was investigated in a planned experiment of 33 rounds. Both the cutting speed and roughness were analysed. The surface morphology of the machined pieces was examined with electron microscopy and the subsurface layer with cross-sectioning of the samples. A lamella was made for transmission electron microscopy to perform a detailed analysis of the chemical content. There was no sample made that would not result in cracks of 20–30 µm depth. These cracks let us assume that the service life of the parts machined in this way will be limited. Multi-criteria optimisation was used to find the optimum machining parameters, which allows the cutting speed to reach 3.2 mm/min and for Ra to reach 2.1 µm.