Fretting Corrosion Behavior of Additive Manufactured and Cryogenic‐Machined Ti6Al4V for Biomedical Applications

Abstract

Metal ion release, caused by synergistic effect of wear and corrosion, is one of the major concerns related to the prostheses lifetime. In this work, samples of additive manufactured Ti6Al4V are machined under dry cutting and cryogenic cooling conditions and their performances in terms of corrosion and fretting corrosion response are investigated. A wet and temperature-controlled apparatus equipped with an electro-chemical cell is designed and set-up in order to evaluate the fretting corrosion effect acting at the interfaces. The obtained results show that the cryogenic machining improves the corrosion and fretting corrosion behavior of the investigated additive manufactured Ti6Al4V

Machining of biocompatible materials — Recent advances

“…33 [12,59]. For surface generation, conventional milling and drilling are commonly used in the production lines for polymer-composite machining [91,120], which, however, could introduce severe subsurface damage and high cutting forces [16,92,120]. An effective way to minimise these effects is to employ abrasive machining, e.g.…”

“…60). Bruschi and co-workers reported in several investigations on the impact of machining parameters and cooling strategies on the wear behaviour [23,24] and tribocorrosion performance [16,17] of wrought and additive manufactured Ti6Al4V alloys for biomedical applications. Wear tests were performed using a cylinder-on-plate configuration in a wet and temperaturecontrolled saline environment (Fig.…”

Mechanical properties and microstructure of a Ti-6Al-4V alloy subjected to cold rolling, asymmetric rolling and asymmetric cryorolling

“…Eqs. (1)- (5) suggest that dislocation density during deformation increases with higher shear strain and lower temperature. Consistent with this prediction, the apparent dislocation cell density in Ti-6Al-4V alloy subjected to asymmetric cryorolling was observed to be higher than that resulting from asymmetric rolling, and it is lowest in the alloy subjected to cold rolling with the same rolling reduction.…”

“…Cryogenic cooling allowed a reduction in the adhesive wear mechanism of Ti-6Al-4V used on the tool cutting surfaces [4]. Bertolini et al [5] found that cryogenic machining improves the corrosion and fretting corrosion resistance of Ti-6Al-4V alloy fabricated by additive manufacturing. Huang et al [6] used thermo-hydrogen processing to improve the mechanical strength of Ti-6Al-4V from 930 MPa to 1160 MPa.…”

Sustainability in bio-metallic orthopedic implants

“…Orthopedic implants, in contrast to a transplant which are biological products, are humanmade products. The surface of implants which comes in contact with the live tissues, cells or blood should be essentially made of a biomedical metal such as titanium or titanium alloy for eradication of rejection or infection [2,21,22]. Titanium has acceptable mechanical properties and has been used for orthopedic implants, yet for still better performance titanium is alloyed with small amounts of aluminium and vanadium (Ti-6Al-4V), typically 6% and 4% respectively, by weight [3,23,24].…”