Author : Rahul Bhatti and Rupinder Singh

Hard Turning is a technique can be used in machining the steel with hardness greater than 45 HRC (hardness on the Rockwell test c-scale). We consider AISI H11 as work piece and Multi-coated carbide TH1500 (CVD) as cutting tool. For this experiment, the L9 Taguchi method is used. The Taguchi method is an Experimental design technique, which is useful in reducing the number of experiments dramatically by using an orthogonal array and also tries to minimize effects out of control. During an investigation the cutting conditions for an experiment are Speed = 100, 120 & 140 m/min, Feed = 0.1, O.2 & O.3 rev/min , D.O.C = 0.2, 0.4, & 0.6 mm . It is observed that the tool wear (flank wear) is mainly effected by the cutting speed is found to be the most contributing factor with percentage contribution of 89.83% while in case of surface roughness also the cutting speed is found to be the most contribution factor with 67.11%. The optimized machining condition for minimizing tool wear from Taguchi Method are: cutting speed 100 m/min, feed 0.20 mm/rev, depth of cut 0.60 mm with an estimated flank wear 130 μm. The optimized machining condition for minimizing tool wear from Taguchi Method are: cutting speed 120 m/min, feed 0.20 mm/rev, D.O.C 0.25mm with an estimated surface roughness of 0.86 μm. Also, CVD Multi-coated carbide cutting tool inserts employed in current investigation have been observed to be an economical alternative to costly CBN, PCBN, Ceramic tools, for continuous hard turning application over the range of parameters selected for this study. In future, the effect of varying in work piece hardness may also be investigated. The Chips forms using the same material with CVD Multi-coated Carbide cutting tool inserts may be carried out to improve machining performance.

Keywords: Flank wear, Taguchi, PVD, CVD & Surface roughness

Article published in International Journal of Current Engineering and Technology, Vol.5, No.4 (Aug-2015)