Impact of work hardening, tool wear and geometry response on machinability during turning AL-6XN super austenitic stainless steel: a work hardening and wear studies on AL-6XN alloy

This work aimed to identify the work-hardening regions in shear zones when the AL- 6XN super austenitic stainless steel alloy was machined using a turning machine. A quick-stop approach was used to generate frozen chip roots. Two cutting speeds of 94 m/min and 65 m/min, a feed rate of 0.2 mm/rev and depth of cut of 1 mm were applied in this study. Microhardness measurements were executed in the hardening region (workpiece–shear zone–chip zone). Results showed that the hardness values were significantly increased in the primary shear zone and the formed chip. The wear of the cutting tool used to machine the alloy was investigated using scanning electron microscope. Excessive notch wear was located on the cutting edge when 65 m/min cutting speed was utilized while at 94 m/min cutting speed, the cutting edge was completely damaged as a flake of the edge was removed due to hard cutting processes. The profile measurement of the cutting tool was executed using an optical profilometer to reveal the changes in the cutting edges locations and profiles and their implication on machining process.