Modelling and analysis of process parameters in drilling of Ti-6Al-4V using response surface methodology (RSM)

Titanium being one of the hardest elements is very tedious to be machined. It is considered as hard to cut metal. One of the major reasons for the difficulty in machining titanium is the development of high temperature while machining of titanium and its alloys. This enormous temperature will negatively impact the machining tool and eventually the operation will fail. Hence optimum process parameters play a pivotal role in the machining of hard to cut metals like titanium. In the present work the authors have attempted to perform drilling operation on the grade 5 alloy of titanium (Ti-6Al-4V) using cobalt drill bits. The process parameters are selected accordingly that the machining operation is completed without any defects and failures. The speed is fixed at 400, 600 and 800 rpm and feed rates are selected as 20, 40 and 60 mm/min for the drilling of a Ti-6Al-4V plate with cobalt drill bits with three different diameters as 6, 8 and 10 mm. The output responses of thrust force, torque and temperature are measured. The output responses are modelled and analyzed using Response Surface Methodology (RSM).