Chip Morphological Behaviour During Machining Of Ti-6Al-4V Using Refrigerated Soluble Oil

Abstract

Chips formed during machining are a vital instrument for the assessment both of machinability of material and the effectiveness of the machining method adopted. Various approaches have been proposed by researchers to make machining Ti-6Al-4V easier, ranging from reduction of cutting speed and feed rate to the use of coolant during machining. In this study, investigatation of the effect of refrigerated soluble oil on machinability of Ti-6Al-4V via monitoring of the chips formed during the various machining processes was carried out. The chips formed for various machining conditions were collected using a designed chip receptor medium and was analyzed using a metallographic microscope with an attached stylus. The experiment was planned using central composite designs (CCD) of the Response Surface Methodology (RSM) resulting in a 20 experimental run plan for dry and wet machining. Machining factors considered were cutting speed, feed rate, depth of cut and coolant temperature with corresponding values 40-120 m/min, 0.05-0.20 mm/rev, 0.2-1.0 mm and 5-11°C respectively. Responses monitored chip thickness, tooth profile and peak height. The effect of various factors on responses were discussed. Basically, results show that chip diameter increased with an increase in cutting speed. However, the sawtooth profile on chip reduced with an increase in cutting speed. It was therefore concluded that coolant temperature has an effect on chip morphology during machining of Ti-6Al-4V using refrigerated coolant.