Fretting wear between titanium alloy components in aero engine is prevailing in the blade dovetail, the blade crown, and the damping shoulders. In this study, the fretting wear behavior of Ti-6Al-4V alloy was investigated by changing the load and displacement under a high frequency (100 Hz). To simulate the actual working conditions in aero engines, both the ball and flat samples were Ti-6Al-4V alloy. It was found that as the load increased, or as the applied displacement decreased, the fretting regime changed from gross slip regime to partial slip regime. The coefficient of friction/traction at steady stage decreased as load increased. Wear scar morphologies varied with fretting running conditions. In gross slip regime, the central area was higher than the rest region of the wear scar. In the mixed slip regime, large material accumulation could be found at both ends of the reciprocating motion. In partial slip regime, a nearly original fretting sample surface was observed in the central area and wear occurred in the edge area. Furthermore, considering the wear of the paired samples, a method based on the fretting wear scar diameter was proposed to evaluate the fretting running conditions.

Several criteria for fretting wear behavior evaluation have been established since the proposal and establishment of the fretting loop concept. In this article, system deformation and system deformation ratio were defined. In addition, the fretting running conditions were distinguished from the evolution of system deformation with fretting cycles during fretting wear tests under different applied displacements and loads. In the gross slip regime, the system deformation was independent of the applied displacement and increased as the load increased, whereas in the partial slip regime, the system deformation was independent of the load and increased with the applied displacement. Furthermore, a linear relationship between the system deformation and the applied load in gross slip regime was found for the first time. Based on this linear relationship, the system deformation ratio can forecast the running regime with a given load and displacement. For the titanium alloy fretting pairs studied in this article, the fretting wear was found to run in the gross slip regime if the system deformation ratio was smaller than 0.9. Based on these observations, the system deformation ratio exhibited applicability in assisting the mechanical design of equipment suffering from fretting wear.

This study presents a mechanistic investigation into the fretting wear behavior of Ti6Al4V alloy with grid-like laser surface textures, focusing on the interplay among texture geometry, debris behavior, and subsurface deformation. Fretting tests were conducted in a ball-on-flat configuration under loads of 20–100 N. Results show that texture-induced modifications of debris dynamics and stress distribution govern the fretting response in both gross and partial slip regimes. In gross slip, dense and deep textures exacerbate adhesive wear by entrapping debris and reducing its protective role, thereby increasing the coefficient of friction. Under partial slip, the same textures facilitate plastic flow and micro-crack initiation at groove edges, leading to layered material separation and early stabilization of slip. Pit filling mechanisms are shown to be orientation-dependent: perpendicular grooves experience crack propagation and lamellar fracture, while parallel grooves exhibit gradual material flow resulting in coherent filler layers. System deformation measurements and SEM analysis further correlate texture parameters with localized damage modes. These findings provide deeper mechanistic insight into how surface texturing influences fretting wear processes in titanium alloys, offering a foundation for texture optimization based on tribological regime and microstructural response.

High-power impulse magnetron sputtering (HiPIMS) technology was used to deposit Ti-Nb-Cr films on Si (100) and 316L substrates by changing the peak power of the Ti-Nb-Cr target. Optical emission spectroscopy (OES) was used to study the effect of peak power on the ion atomic arrival ratio in front of the substrate. Experimental instruments such as an X-ray diffraction (XRD) device, scanning electron microscope (SEM), transmission electron microscope (TEM), nanohardness tester, ball-disk reciprocating friction machine, and electrochemical workstation were used to study the effects of the atomic arrival ratio of Ti, Nb, and Cr ions on the microstructure, mechanical properties, and corrosion resistance of Ti-Nb-Cr films. The results show that when the peak power is 67.84 kW, the ion atomic arrival ratio of Ti reaches 47.57%, the ion atomic arrival ratio of Nb reaches 39.41%, and the ion atomic arrival ratio of Cr reaches 10.6%. The ion atomic arrival ratio is doubled compared to the peak power of 51.04 kW. The films prepared at different peak powers all show diffraction peaks of the BCC structure. At high power levels, the TiNbCr films exhibit reduced residual compressive stress, although this may be accompanied by lower hardness and wear resistance.