Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

Abstract

The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly-developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence x-ray diffraction (GI-XRD) and x-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks' solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

A Preliminary Study to Enhance the Tribological Performance of CoCrMo Alloy by Fibre Laser Remelting for Articular Joint Implant Applications

“…Figure 11 shows the XRD profile for the laser-treated and untreated surfaces. It is important to point out that the penetration depth of the radiation into the material surface is typically a few μm in the XRD measurement [27]. The penetration depth is between 0.8 and 1.9 μm in our XRD (refer to Section 2.3).…”

“…We have recently demonstrated that laser surface remelting (hereafter, called laser remelting) of metallic materials, for example titanium or titanium-based alloys, leads to a greatly enhanced wear-resistance [27,28]. Meanwhile, corresponding studies on CoCrMo surface are relatively rare.…”

Corrosion and bioactivity performance of graphene oxide coating on Ti Nb shape memory alloys in simulated body fluid

“…In addition, laser treatment escalates the adhesion strength between GO coating and the substrates, which enhances the barrier effect of the coating, and further improves the corrosion resistance of laser/GO-coated sample. In this view, Chan et al [49] indicated that a more protective oxide film with higher crystallinity can be obtained by laser surface treatment compared with the air-passivated oxide film formed on the untreated surface. The EDX analysis of GO-coated and laser/GO-coated samples showed that apart from the presence of the expected elements (Ti, Nb, Ca, P, O, and N), a large amount of carbon was also detected that is related to the presence of GO.…”

“…Another study [49] demonstrated that reduced graphene oxide reinforced composite coatings on copper substrate can increase the corrosion resistance. In addition, laser treatment escalates the adhesion strength between GO coating and the substrates, which enhances the barrier effect of the coating, and further improves the corrosion resistance of laser/GO-coated sample.…”

“…Chan et al [49] demonstrated that the laser can treat the specific area accurately with high bonding strength between the substrate and treated film to avoid the delamination at the interface. A corresponding increase in polarisation resistance (R P ) from 1.8 kΩ·cm 2 (for the…”