Machinability performance investigation in CNC turning of Ti–6Al–4V alloy: Dry versus iron-aluminium oil coupled MQL machining comparison

Abstract

Ti–6Al–4V is the largest useable titanium grade alloy in various engineering components due to its superior inherent properties like high strength to weight ratio, highly corrosive resistance, ability to withstand high temperature, etc. But machining of this alloy is found to be challenging because of having lesser thermal conductivity, highly chemical sensible, more sensitivity in work hardening and low young's modulus. However, the current study offers the use of novel and environment pleasant lubricants like iron aluminium oil with minimum quantity lubrication (MQL) concept to machine this alloy using a low budget hard tool (uncoated carbide) and the performance was compared with dry machining. Severe abrasion, adhesion, diffusion, and chipping were the main cause of tool failure in both cooling strategies. The tool life in MQL was traced to be 280% greater than the dry condition at the same turning parameters. Compared to dry turning, lower tool vibration and superior surface quality were obtained in MQL. The MQL assisted turning exhibited 12.38% lower costs than dry. Overall, with the use of an uncoated carbide tool, the turning of Ti–6Al–4V alloy in MQL was found to be more precise and more economical than dry and recommended for mass production works.

Keywords

• Ti–6Al–4V
• Flank wear
• Tool vibration
• Surface roughness
• Cutting cost