Comparison of the Effects of Vegetable Oils such as Castor and Canola Oil and Polyol Esters on the Metalworking Performance of Ti-6Al-4VAlloy by Tapping Torque Method

Abstract

Ti-6Al-4V material is an alloy of particular interest for engineering applications in a wide range of industries, especially aerospace and medicine, due to its outstanding corrosion resistance, favorable strength-to-weight ratio and biocompatibility properties. Due to the low thermal conductivity and high chemical reactivity of this alloy, its machinability is quite limited and is therefore referred to as the "difficult-to-cut" alloy. When the problems encountered in the processing of Ti-6Al-4V alloy are evaluated, the preparation of the appropriate cutting environment, ensuring optimum cutting parameters and the use of appropriate coolant are the priorities in overcoming these problems. Vegetable oil and polyol esters are biodegradable base fluids that can be used as a sustainable alternative to petroleum-derived oils in many lubricant applications. In this study, the effects of castor and canola oils and trimethylolpropane trioleate (TMPTO) and trimethylolpropane trioleate complex (TMPCX), neopentyl glycol (NPG) and pentaerythritol tetra-oleate (PE-TO) type polyol esters on the machining performance of Ti-6Al-4V alloy were investigated using the Tapping Torque test method. In the tests performed on Ti-6AL-4V, it was determined that the tapping performances of TMP-TO, TMP-CX, PE-TO and castor oil were close to each other and gave the best results. It has also been determined that the tapping performance of canola oil is lower than these oils. NPG-DO gave a striking result for Ti-6AL-4V and the tapping performance was found to be very low.