Tool wear assessment in dry machining of Ti-6Al-4V using Taguchi approach

Abstract

Titanium alloys (Ti-alloys) are valued for their lightweight, high strength-to-weight ratio, and corrosion resistance, but they present machining challenges. Optimizing cutting parameters and tool selection is essential for improving machinability and surface integrity, particularly in aviation and biomedical applications requiring precision. A key issue in metal cutting is the high temperature at the tool-chip interface, which can lead to stiction and tool failure. This study evaluates the performance of bare, textured, and TiN-coated WC–Co tools in dry turning of Ti–6Al–4V alloy. Advanced microscopy techniques were employed to analyze tool wear. Using the Taguchi method for Design of Experiments (DoE), varying cutting speeds (Vc) and depths of cut (DoC) were analyzed with MINITAB 22. Textured tools exhibited enhanced wear resistance with increased DoC, while TiN-coated tools excelled at lower Vc. Energy dispersive X-ray (EDX) analysis indicated stiction issues in both tool types due to titanium’s solubility in the cobalt matrix, impacting tool longevity. Optimal cutting parameters were identified at Vc = 80 m/min and DoC = 0.25 mm, achieving flank wear (VB) below 300 µm, in line with ISO standards. This study underscores the significance of DoC in tool wear, highlighting that lower cutting speeds and greater DoCs yield optimal machining conditions for Ti–6Al–4V. Both texturing and coating enhance tool life and wear resistance, with texturing showing particular promise for future exploration.