Chip formation in monocrystalline iron-aluminum

Iron-aluminum has an excellent corrosion resistance, low density and high specific strength compared to conventional steel. In addition, the raw materials and manufacturing costs of iron-aluminum alloys are relatively low. However, the machinability is challenging. Economical machining of iron-aluminum is currently not possible due to high tool wear. Furthermore the cutting and chip formation mechanisms in machining of iron-aluminum alloys are not fully understood.To understand the thermomechanical mechanisms in the material separation process the influences of the crystal lattice orientation on the chip formation is analyzed in relation to the cutting direction. Therefore, monocrystalline FeAl specimens are machined, using a simultaneous measuring device existing of a two-color ratio pyrometer, piezoelectric force measurement as well as microcinematographic images. The observed trend is that the segmentation as well as the chip thickness are significantly influenced by the lattice planes engaged in the cut. The causes for the different chip formation mechanisms are ascribed to a change of the slip planes and slip vectors activated in relation to the load on the crystal lattice as well as the orientation of the crystal lattice to the load.