Processing of Titanium by Machining: A Closer Look Into Performance Metrics in Bio-Fabrications

Abstract

Titanium alloys have various applications in biomedicine, aerospace, marine, energy, and chemical industries. A titanium plate for cranioplasty is considered to be safe for implantation in humans. Machining of titanium alloys is very challenging because of their high-temperature strength, low thermal conductivity, low modulus of elasticity, high stresses at the tool edges, the strong chemical affinity of titanium to the cutting tool materials resulting in built up edge formation, high temperature during machining, and high tool wear. This article represents an extensive review on machining of titanium alloys considering the effect of machining parameters on chip formation, cutting force, tool wear, heat generation, surface integrity (surface defect, microstructure, and surface roughness), mechanical properties (hardness, residual stress, and fatigue) and biomedical performance (corrosion resistance, residual stress, and cell growth). Various cooling systems, vibration assisted machining, and laser assisted machining can enhance the machinability of Ti alloys. Minimum quantity lubrication with nanoparticles (MQLN) has the best performance among various cooling systems. Moreover, the future research directions are presented in this work.