Mild wear and severe wear behavior of Ti-6Al-4V alloy at low, intermediate and high sliding speeds

Abstract

This paper described the mild and severe wear behavior of Ti-6Al-4V alloy and revealed the mechanisms for mild-severe wear transitions (MSWTs) under low, intermediate and high speeds. Under each speed, wear rate was measured as a function of applied load, from which mild wear and severe wear were identified. Morphologies and chemical compositions were analyzed on worn surfaces using SEM and EDS to determine the wear mechanisms and their relation with wear transition. Analyses of microstructural evolution and hardness change in subsurfaces were performed to explore the mechanisms for MSWTs. Results showed that two different types of MSWTs were found: one was controlled by large-scale spallation of mechanically mixed layer (MML) under 0.2 m s −1 ; the other one was dominated by severe plastic deformation (SPD) under 0.8 and 2.0 m s −1 . The former mechanism for MSWT was the enhanced fragility of MML with an incompact structure owing to high content iron oxide, while the latter mechanism for MSWT was the softening of surface material deriving from dynamic recrystallization during sliding wear testing. The results of this investigation shed new insight into the relationship between experimental parameters, wear mechanism, microstructure and property in subsurface and MSWT for Ti-6Al-4V alloy.

Elevated-temperature wear behavior of Ti6Al4V alloy: microstructural evolution and properties change in subsurfaces and mild-severe wear transition

“…The drop gap was in the range from 30 HV to 35HV, thus the worn surface was obviously softened in the severe wear regime. The present surface hardness variation in mild and severe wear regimes is similar to the results of Ti6Al4V alloy during sliding at 0.8 and 2.0 m s −1 and 20 °C in previous study [28]. It can be inferred that the commencement of SPD wear mechanism may have been driven by surface softening.…”

A comparison of wear between unidirectional and reciprocating sliding motions under different applied loads and lubricants

“…Tribological research is of great significance for exploring new lubricant and wear-resistant materials and selecting suitable tribo-pairs. Currently, most of the research focuses on the tribology under special conditions, such as vacuum [1], high temperature [2][3][4], heavy load [5], high speed [6][7][8][9], etc, or the tribology of new materials, such as super-lubricant materials [10], 2D nanomaterials [11], diamond-like carbon (DLC) coatings [12][13][14], etc. However, less attention is paid to the wear difference between reciprocating sliding motion (RSM) and unidirectional sliding motion (USM) in the friction system, which increases the difficulty for selecting suitable lubricants or judging the wear resistance of materials as the wear mechanism of two sliding motions is not clear.…”