Tribological Behavior of Titanium Alloys in Demanding Environments

Titanium alloys are widely used in demanding applications due to their excellent strength-to-weight ratio, high-temperature strength, and corrosion resistance. While the manufacturing, production, and mechanical properties of titanium alloys have been widely studied over the last decades, their wear and frictional behaviour have received little attention. Understanding the tribological behaviour of these alloys is critical as the endurance life of several mechanical systems within a gas turbine engine is limited by the frictional and wear behaviour due to the presence of many complex contacting and mobile assemblies. The main purpose of this study is to provide a better understanding of the tribological behaviour of titanium alloys as well as critically examine their interfacial phenomena under various operating conditions. The tribology testing is performed using a reciprocating tribometer using different temperatures and contact conditions. Subsequently, ex situ analysis is performed on the worn surfaces using X-ray diffraction, field emission scanning electron microscopy and energy dispersive spectroscopy. Similarly, the transferfilm behavior on the counterface is thoroughly investigated for the different conditions. The frictional and wear behavior are correlated to the interfacial processes and in particular, the formation of oxides on the worn surfaces.

Keywords: Aerospace Materials, Alpha-case, Interfacial Processes, Tribology, Titanium Alloys, Wear