Amelioration of the tribological behaviour of carbon/Ti–6Al–4V and graphite/Ti–6Al–4V couples by plasma nitriding of the titanium alloy

Abstract

This article reports on the influence of nitriding treatment of titanium alloy on the tribological behaviour of amorphous carbon or graphite/Ti–6Al–4V couples. This contact was investigated in pin-on-disc geometry in an ambient atmosphere. The pins were made of amorphous carbon or graphite and the discs were made of Ti–6Al–4V, nitrided or not. The treatment of nitriding for this study was an N2–H2 plasma nitriding at a low temperature (700 °C) for 12 h. In these conditions, the top surface hardness was improved by a factor of 3. In this study, the mechanism of transfer and wear of carbon against Ti–6Al–4V, nitrided or not, has been studied with a scanning electron microscope, an optical microscope, etc. The analyses show that the nitriding of Ti–6Al–4V improves the tribological behaviour of the couples investigated. In fact, with the disc made of Ti–6Al–4V, the wear of carbon is very high and the disc is worn down at the end of the test. In contrast, after nitriding of the disc, the wear of carbon decreases, and there is a carbon film transfer on the disc. Moreover, with the nitriding of Ti–6Al–4V, the friction coefficient is stabilized, whereas without the nitriding of Ti–6Al–4V, the curve of the friction coefficient is marked by a very important increase during a short time. With the pin in graphite, the nitriding decreases the friction and increases the adhesion on the disc. Furthermore, the tests have shown that the contact temperature increases with the nitriding of Ti–6Al–4V.

The effect of laser surface texturing on the tribological behavior of Ti-6Al-4V

“…5 Generally, the surfaces of Ti-alloys could be modified using either of two ways: modifying surface layers based on substrate material or deposition of coatings with excellent tribological properties. Thermochemical diffusion treatments 6 and ion implantation 7,8 could attain the first objective by forcibly adding some elements (N, O and C) into the substrate metallurgical structure. However, the efficiency is low, which can be attributed to long operating time and high energy consumption.…”

Synergetic effect of oleophilic textured surfaces and MoS2 on the tribological properties of Ti-6Al-4V alloy under dry and lubricated sliding conditions

“…The first involves altering the surface layers based on the substrate material, while the second involves applying coatings with superior tribological properties. The first method can be achieved through thermochemical diffusion treatments [14] and ion implantation [15,16], which forcibly introduce certain elements (such as N, O, and C) into the metallurgical structure of the substrate. However, this approach is not particularly efficient, as it requires a significant amount of time and energy.…”

Improvement of the tribological properties of pure Ti by laser cladding intermetallic compound composite coating

“…Ti and Ti-alloys are now expanding rapidly into many fields, such as aeronautical, chemical industries, marine, power generation, sports and leisure, transportation, and biomedical devices. This is due to their high strength and excellent corrosion resistance, low density, high strength-to-weight ratio, low modulus, and good biocompatibility [1][2][3][4][5][6][7][8][9][10][11]. However, the poor tribological properties of Ti and Ti-alloys: highfriction coefficient and low hardness, greatly limit their engineering applications [12][13][14].…”