Machinability studies of Al–4Mg/in-situ MgAl₂O₄ nano composites: measurement of cutting forces and machined surface roughness

Abstract

The present research is to study the dry turning machinability characteristics of in situ Al-4Mg/MgAl2O4 nanocomposite by High-Speed Steel tool. The influence of various machining process parameters, such as feed rate, depth of cut and cutting speed on the surface roughness and cutting force of the nanocomposites was measured while performing dry turning. From the turning operation results, it is noticed that up to 100 m/min, the cutting force increased and with further increases in cutting speed, the cutting force starts decreasing up to 150 m/min. Using a scanning electron microscope, the type of chips and built-up edge (BUE) development were studied. Formations of BUE were noticed to be higher at low cutting speeds (50 m/min) and lower at high cutting speeds (150 m/min). At a given depth of cut and feed rate, with an increase in cutting speed, the length of the chip and chip curls increased. Further, higher 2 wt.% of in-situ MgAl2O4 addition changes long-curled chips to segmental type chips. With a feed rate of 0.14 mm/rev, the Al-4Mg / 1wt% MgAl2O4 nanocomposite showed the lowest surface roughness value of 2.4 µm proving usage of high speed steel can provide better surface finish while turning Al-4Mg / MgAl2O4 nanocomposite.